This paper discusses the reaction mechanism of methane dry reforming (DRM),including the microscopic mechanism of the key steps and the main factors affecting the reaction path.The properties and characteristics of various catalysts used for DRM,including metal oxide and metal carbide as support catalysts,and precious metal and Fe,Co,Ni as active component,are comprehensively evaluated,and their advantages and disadvantages in catalytic activity,selectivity and stability are analyzed.In addition,this paper also focuses on the mechanism of additives in improving catalytic performance,and how to optimize the overall performance of catalysts by regulating the type and dosage of additives.Finally,the application status of methane dry reforming technology in industrial production is summarized,and the future development direction is proposed.

Excessive emissions of carbon dioxide have caused serious environmental problems,especially global warming and ocean acidification.The electrocatalytic CO₂ reduction reaction (CO₂RR) is one of the most promising methods for converting CO₂ into high-energy-density fuels or high-value chemicals. Because of their low cost and high selectivity for C₃ products,copper-based catalysts have garnered a lot of attention as efficient electrocatalysts for the reduction of carbon dioxide to multi-carbon compounds.This paper summarizes the research progress of copper-based catalysts for CO₂RR to generate C₃ products in recent years,including the reaction mechanism of CO₂RR to generate C₃ products,and improving the electroreduction performance of copper-based catalysts through structural regulation,surface regulation,bimetallic and other strategies.Finally,the key challenges and future research directions in this field are outlined to provide ideas for further development of highly active CO₂RR catalysts to generate C₃ products.

As a functional material,white carbon black has a broad application prospect in the traditional rubber,paint,toothpaste,pesticides and other fields,electronic materials,new energy,environmental protection materials and other emerging applications.The production of white carbon black in China has abundant raw material advantages,a large number of crops and industrial wastes as white carbon black is one of the main economic sources of white carbon black silicon source,which makes the production of white carbon black has low raw material price and high added value economic benefits.At present,the downstream consumption structure of the carbon black industry accounts for a relatively large tire,and the application economic value of highly dispersed carbon black is high,and the silicone industry has a strong market potential as one of the downstream industries.In this paper,six kinds of preparation methods of white carbon black (vapor phase white carbon black,precipitation white carbon black,microemulsion white carbon black,sol-gel white carbon black,rice husk and grain extraction white carbon black,non-metallic mineral extraction white carbon black) were reviewed.The preparation technology and research status of white carbon black were analyzed.The green preparation of white carbon black was summarized in detail,with the aim of providing theoretical guidance for solving the existing industrial pollutants.

Dimethyl 1,4-cyclohexanedicarboxylate(DMCD) is an important intermediate for the preparation of polyester monomer 1,4-cyclohexanedimethanol(CHDM).The research progress in aspects such as the reaction mechanism,catalyst types and reaction process of hydrogenation of dimethyl terephthalate(DMT) to produce DMCD is reviewed.The discussion focuses on the process of DMT hydrogenation and the performance of catalysts with different active centers(Pd,Ru,Ni and bimetallic).Finally,the prospects of the future development in catalysts and processes of hydrogenation of DMT is proposed.

Propylene oxide (PO) is an important chemical intermediate mainly used in the production of various organic raw materials such as polyether polyols and propylene glycol,and is widely used in fields such as food and tobacco.The use of titanium silicon molecular sieve (TS-1) as a carrier to load metal gold as a catalyst for gas-phase epoxidation of propylene has broad industrial application prospects.This article mainly introduces the main factors and catalytic mechanism that affect Au/TS-1 catalyst,including the preparation method of the catalyst,gold particle size,and additives.The main preparation methods include immersion method,sedimentation precipitation method,solid grinding method,ionic liquid method,and colloid method,among which sedimentation precipitation method is currently the mainstream laboratory preparation method for catalysts.The main influence of gold particle size is reflected in the 2 nm gold catalytic effect,which is most favorable for the occurrence of propylene epoxidation reaction.The main additives are alkali metals Na and Cs,which can improve the catalytic performance of the catalyst.The Au/TS-1 catalyzed epoxidation of propylene mainly relies on the dual site synergistic catalysis of Au and Ti sites.How to prepare high-performance Au/TS-1 on a large scale is currently the main difficulty in the industrial application of propylene hydrogen phase epoxidation to produce propene oxide.

Taking ExxonMobil for example,this paper examined the patent application trends and technical routes for the related patents of metallocene polyethylene as cataloged in the Derwent patent database.By February 29,2024,ExxonMobil has submitted 175 patent applications related to metallocene polyethylene,including 59 in China.The analysis revealed that ExxonMobil has a comprehensive patent layout,including metallocene catalyst designs,polymerization processes,applications and modifications of metallocene polyethylene.The patent layout of ExxonMobil in China was basically consistent with that in the world.However,ExxonMobil emphasized catalyst design in its global layout,and payed more attention to application technology in its patent layout in China.Combined with the analyzed results above,some suggestions were given for domestic relevant enterprises and research institutions to deploy technical forces.

In this paper,TiO₂ powder and UiO-66 were obtained by sol-gel method and solvothermal method respectively.Then UiO-66@TiO₂ composite photocatalyst was synthesized.Composite nano-photocatalyst UiO-66-NH₂@TiO₂ was prepared by solvothermal method using titanate(C₁₆H₃₆O₄Ti) as the Ti source,2-amino benzoic acid as the -NH₂ source,benzoic acid as crosslinker,and UiO-66 as the carrie.By in situ infrared spectroscopy (FT-IR),ultraviolet diffuse reflection (DRS),field emission scanning electron microscope (SEM),energy spectrum (EDS),N₂ adsorption-desorption,X-ray photoelectron energy spectrum (XPS) and X-ray diffraction (XRD),the structure,morphologe,shape of prepared TiO₂,UiO-66,UiO-66@TiO₂,UiO-66-NH₂ and UiO-66-NH₂@TiO₂ were characterized.Catalytic performance test was applied in photocatalytic degradation of methyl orange (MO) solutions.The test results showed that the degradation of 50 mL 5 mg·L^-1 MO solution in 160 min was 92.35% under the condition of 0.800 g UiO-66-NH₂@TiO₂,and pH=1.Therefore,it can be proved that UiO-66-NH₂@TiO₂ has high photocatalytic activity.

The catalytic hydrogenation of p-chloronitrobenzene to synthesize p-chloroaniline is an important organic chemical reaction,and the key to this catalytic reaction is to realize nitro hydrogenation and reduction without dechlorination.N-doped modified Pt_0.3/N_xC catalysts were prepared by an impregnation method,which showed that the metal-carrier interactions induced by N-doped activated carbon carriers improved the activity,selectivity and stability of the catalysts,while inhibiting the C—Cl bond breakage.Among them,the average particle size of Pt nanoparticles on the surface of the Pt_0.3/N_0.2C catalyst prepared by using a mass ratio of urea to activated carbon of 0.2 was the smallest and uniformly dispersed.The catalyst exhibited excellent conversion (100%),selectivity (99.0%) and reusability for the catalytic synthesis of p-chloroaniline from p-chloronitrobenzene hydrogenation at 50 ℃,0.5 MPa,and a reaction time of 90 min.

As a representative of advanced oxidation processes,electro-Fenton (EF) technology has attracted extensive attention in the removal of organic pollutants due to its safety,simplicity of operation,and environmental friendliness.However,transition metal-based catalysts in advanced oxidation technologies still face problems such as low selectivity,narrow pH applicability range,and high economic costs.Moreover,there is still a lack of in-depth understanding of the regulation mechanism of transition metal-based materials.This paper reviews the research progress on EF technology in the treatment of organic wastewater in recent years,analyzes the reaction mechanism of 2e^- oxygen reduction reaction (ORR) generating H₂O₂ and the activation of H₂O₂ at the solution/catalyst interface to form ·OH in the EF reaction,and discusses the preparation of EF cathode catalysts,the influencing factors of catalytic performance,and the development of multifunctional catalysts.At the same time,in order to solve the inherent problems such as mass transfer limitations,intermittent operation,and insufficient energy utilization,the coupling and synergistic reaction systems of EF technology with other technologies are further discussed.It is expected to provide certain references for the design of EF catalysts and the exploration of EF coupling technologies.

In order to improve the phenomenon of micro-pores caused by water evaporation in the film forming process of epoxy acrylate emulsion,four different oxidized polyethylene waxes XW-17,XE-16,PED522 and 629A were used to modify the epoxy emulsion.Due to the high melting point of oxidized polyethylene wax,it was used as a functional monomer to modify epoxy acrylate,and its optimal amount was studied.Finally,epoxy emulsion was prepared by soap-free core-shell emulsion polymerization.Fourier transform infrared spectroscopy (FT-IR) confirmed that oxidized polyethylene wax was successfully introduced into epoxy acrylate.The optimum addition amount of oxidized polyethylene wax was determined by cross-linking degree and water absorption.The microstructure of emulsion before and after modification was characterized by transmission electron microscopy (TEM).Thermal weight (TGA),static water contact angle and atomic force microscopy (AFM) were used to test the emulsion dry film before and after modification.The results showed that the addition of oxidized polyethylene wax could improve the thermal properties and roughness of the emulsion dry film,but did not change the hydrophilicity of the emulsion dry film.The optimum addition amount of oxidized polyethylene wax to modified epoxy acrylate was mass fraction of 0.3%,and the modified emulsion with 629A had the best performance.

At present,the application of traditional commercial SCR catalysts in the thermal power denitrification industry is relatively mature,but the flue gas temperature is low and components are complex in non-electric industries including glass,cement,steel,and waste incineration,the operating life of denitrification catalysts is generally short.This is because the operating conditions of non-electric industries are special,and the flue gas contains a large amount of SO₂,H₂O,heavy metals,alkali (earth) metals,dust and metal salts,which lead to catalyst deactivation.Researchers study the mechanisms of catalyst poisoning and waste catalysts regeneration methods to improve the operational life of low-temperature catalysts.This article analyzes the poisoning mechanism and deactivation reasons of low-temperature catalysts,and summarizes the methods for anti-poisoning and resource utilization for deactivation catalyst.

The main research and current situation of acetonitrile synthesis in industry are reviewed.Firstly,the industrial application and market scale of acetonitrile are introduced.Secondly,different process paths,catalysts and their industrial applications are summarized,as well as main manufacture factories.The advantages of ethanol ammonia dehydrogenation method are analyzed based on the current trend of industrialization of coal-based ethanol in China.The new research direction of acetonitrile synthesis from ethanol is described in detail,and the catalytic reaction mechanism and research progress of ethanol ammonia dehydrogenation process catalyzed by Cu and Co based catalysts are summarized.Finally,the research direction of catalytic system of this technical route is prospected in combination with the research progress of the author's research group.

In the context of the implementation of the global “plastic restriction order” and the driving force of environmental and green protection,butane-1,4-diol (BDO),as a crucial and natural degradable raw material,is anticipated to receive significant attention from industrial and market sectors.Moreover,BDO is also an important organic raw material,showing widespread applications extend across multiple key fields such as medicine,textile industry,electronic materials,as well as engineering plastics.Here,this review summarizes the major synthetic methods of BDO and the development of its high-value-added products.Meanwhile,the key problems in the industry preparation process of BDO were discussed,additionally,the merits and demerits in each process flow were also put into deep insight.Finally,prospects were put forward for the BDO-industry development combined with the national characteristics and actual situation.

Dimethyl 1,4-cyclohexanedicarboxylate(DMCD) serves as a crucial pharmaceutical intermediate for synthesizing diverse drugs and constitutes an important raw material for polyester production.Ru/Al₂O₃ catalysts were synthesized using Ru as the active center and Al₂O₃ as the support,employing two distinct methods:the impregnation method and the deposition-precipitation method.These catalysts were applied to the selective hydrogenation of dimethyl terephthalate(DMT) to produce DMCD.The catalysts were characterized by XRD,CO₂-TPD,TEM and H₂-TPR.High-performance liquid chromatography was utilized for the quantitative analysis of DMT conversion efficiency and DMCD yield.The results demonstrate that the 3%Ru/Al₂O₃ catalyst prepared via the deposition-precipitation method exhibited superior catalytic performance and stability under the following optimal conditions:a DMT to 3%Ru/Al₂O₃ mass ratio of 10∶1,a reduction temperature of 300 ℃,a calcination temperature of 300 ℃,a reaction temperature of 150 ℃,and a reaction time of 2 hours.Under these conditions,DMT conversion exceeded 99%,and the DMCD yield surpassed 92%.Compared to a commercial Ru/C catalyst,the Ru/Al₂O₃ catalyst displayed faster sedimentation in the product mixture,facilitating easier separation.Furthermore,its catalytic efficiency showed almost no change after five consecutive reaction cycles.

Research progress on catalysts of 4-tertbutylphenol via alkylation of phenol was outlined,and solid acid catalyst,supported solid acid catalysts,resin catalysts and molecular sieve catalysts in the application of 4-tertbutylphenol alkylation were introduced.It was pointed out that the development of catalytic performance and environment friendly alkylation catalysts was the future of 4-tertbutylphenol industrialization research direction.

Layered bimetallic hydroxide (LDH) has become an excellent candidate material for water electrolysis catalyst due to its unique layered structure.Nickel-cobalt layered bimetallic hydroxide (NiCo-LDH) was in-situ constructed on 3D printed nickel mesh (3D-NM) by electrodeposition method,and the regulation of the bimetallic nickel-cobalt ratio on the morphology and electrocatalytic oxygen evolution performance of the bimetallic layered hydroxide (NiCo-LDH) was investigated.When the ratio of Ni∶Co is 1∶1,NiCo-LDH nanosheets exhibit the best oxygen evolution activity,the required overpotential at 10 mA·cm^-2 current density is only 230 mV,the Tafel slope is 103.3 mV·dec^-1,and the nanosheets have a large electrochemically active surface area.The catalyst also showed excellent catalytic stability during a 30 h test.This excellent oxygen evolution activity can be attributed to the abundant electrochemical active sites provided by NiCo-LDH nanosheets and the good charge transport capacity,which together promote the effective charge/electron transfer,thus significantly improving the efficiency of water electrolysis.This study provides a new way for high throughput preparation and optimization of layered bimetallic hydroxide electrocatalysts.

Ester hydrogenation reaction plays a crucial role and is a key step in the synthesis of various high value-added chemicals in modern chemical industry.Especially,in the process route of coal to ethanol and ethylene glycol,the hydrogenation of methyl acetate and dimethyl oxalate is the core step of the process,which is of great significance for promoting the diversification and clean development of coal resources in China.Copper based catalysts are widely used in industrial production for ester hydrogenation reactions due to their advantages of low cost and high selectivity.However,due to the low Tammann temperature of Cu,copper based catalyst nanoparticles (NPs) are prone to aggregation,leading to a decrease in activity.In order to achieve space-time yield in industrial production,it is necessary to increase the reaction temperature,which accelerates the deactivation of copper based catalysts.Researchers usually use methods such as doping additives and developing morphology confinement to hinder the high-temperature aggregation of Cu NPs,in order to maintain the activity of the catalyst and improve its service life.This article elaborates on the mechanism of action of copper based catalysts and the influencing factors of ester hydrogenation reactions.It reviews the research progress of copper based catalysts for ester hydrogenation and introduces typical industrial applications of ester hydrogenation.

A series of tungstovanadophosphoric heteropolyacid catalysts H₄PW₁₁VO₄₀,H₅PW₁₀V₂O₄₀,H₆PW₉V₃O₄₀ and H₆P₂W₁₈O₆₂ were prepared by conventional aqueous solution and ether extraction methods.And the structures of tungstovanadophosphoric heteropolyacid catalysts were characterized by powder X-ray diffraction (PXRD) and infrared spectroscopy (FT-IR).The tungstovanadophosphoric heteropolyacid catalysts were used in the catalytic synthesis of tributyl citrate,and the effects of different heteropolyacid structures,reaction temperature,alcohol/acid molar ratio,catalyst dosage on the esterification of tributyl citrate were investigated.The results showed that H₆P₂W₁₈O₆₂ had the highest catalytic activity,and the average esterification of tributyl citrate could reach up to 95.9% when reaction temperature was 150 ℃,alcohol/acid molar ratio was 4∶1,and catalyst dosage was 0.15 g.

Ethylene oxide (EO) is a pivotal derivative in the ethylene industry,which is next to polyethylene in importance.Silver (Ag)-based catalysts exhibit exceptional performance in the epoxidation of ethylene to EO.The RS-891 catalyst,synthesized via the impregnation method,was characterized using X-ray diffraction (XRD),scanning electron microscopy (SEM),mercury intrusion porosimetry,X-ray photoelectron spectroscopy (XPS),and oxygen temperature-programmed desorption (O₂-TPD) to elucidate its structural and chemical properties.The catalytic performance of RS-891 in the epoxidation of ethylene to produce EO was systematically evaluated.The results demonstrate that the α-Al₂O₃ support utilized in the RS-891 catalyst possesses a lamellar structure with an interlocking configuration,which enhances the mechanical strength of the support and promotes the uniform dispersion of silver nanoparticles.This structural feature effectively mitigates nanoparticle aggregation,thereby extending the operational lifespan of the catalyst.Laboratory evaluations conducted over 1 500 h,corroborated by industrial operational data,indicate that the RS-891 catalyst achieves an EO selectivity exceeding 88% after 100 h of operation,with a consistent upward trend in selectivity thereafter.Once selectivity surpasses 88%,the catalyst maintains stable and reliable performance,ensuring high catalytic efficiency.The close alignment between industrial application data and laboratory results underscores the exceptional stability of the RS-891 catalyst,highlighting its significant potential for industrial applications and substantial economic value.

As a kind of non-CO₂ greenhouse gases,hydrofluorocarbons (HFCs) have a global warming potential (GWP) ranging from hundreds to tens of thousands of times higher than that of CO₂.Consequently,it is urgent to develop effective emission reduction measures to mitigate HFCs emissions.However,direct elimination methods fail to fully recover and utilize the valuable fluorine (F) resources contained in HFCs.As fourth-generation refrigerants,hydrofluoroolefins (HFOs) are characterized by shorter atmospheric lifetime and significantly lower GWP,making them superior alternatives to HFCs.Simultaneously,HFOs serve as critical feedstocks for high-value fluorochemical products,including fluorinated electronic chemicals and fluoropolymers.The gas-solid phase catalytic dehydrofluorination (DHF) process,which converts HFCs into environmentally friendly HFOs,represents the most promising approach.The success of this technology hinges on catalyst development.Current research focuses on four catalyst categories: non-metal catalysts (e.g.,activated carbon-based materials) offer low-cost advantages but suffer from poor regeneration efficiency and stability.Cr-based catalysts demonstrate exceptional dehydrofluorination activity but face environmental concerns due to excessive acidity and potential Cr leaching.Mg-based catalysts show high selectivity,though their complex synthesis processes hinder scalability.Al-based catalysts stand out for their tunable acidity,environmental benignity,and balanced performance,making them the current research priority.Future advancements should prioritize catalyst design with optimized acidity,hierarchical porosity,and enhanced resistance to coking,aiming to achieve high activity,longevity,and industrial applicability to effectively promote the control of HFCs emissions and their resource utilization.

Mechanical strength serves as a critical prerequisite for solid catalysts to exhibit optimal performance,while forming processes provide solid-phase catalysts with appropriate morphology,dimensions,and superior mechanical robustness.Among various forming techniques,extrusion molding has been extensively employed in the processing of catalytic materials and ceramic products due to its advantages of high production efficiency,process continuity,cost-effectiveness,and broad applicability.During catalyst extrusion molding,mechanical strength is influenced by multiple factors related to forming conditions and thermal treatment processes.This paper systematically reviews the fundamental mechanisms of catalyst extrusion molding,operational parameters during extrusion,and heat treatment procedures.Key influencing factors and corresponding control strategies are discussed,including powder particle size,mixing duration and methodology,water-to-powder ratio,peptizing agents,extrusion aids,binding agents,as well as drying and calcination processes.These investigations hold significant implications for fabricating stable and controllable high-strength catalysts while extending the operational lifespan of industrial catalysts.

Metal-organic frameworks materials(MOFs) have garnered significant attention in energy conversion and environmental catalysis due to their high porosity,tunable structures and multi-functionality.As a typical representative of zirconium-based MOFs,UiO-66 has attracted significant attention in the research of functional MOFs in recent years due to its unique zirconium oxide cluster structure,which demonstrates excellent thermal stability,chemical stability and structural modifability.Benefiting from its highly ordered crystalline structure and diverse modification strategies,functionalized UiO-66 has shown great application potential in electrocatalytic reactions.This paper systematically summarizes the synthesis methods,performance optimization strategies of UiO-66 and its application progress in the field of electrocatalysis,points out the challenges faced by UiO-66 material research at the present stage and the future research focus directions,in order to promote the practical application of UiO-66 in the fields of energy and environment.

Silver catalyst is the only industrial catalyst for the production of ethylene oxide (EO),but there are problems such as complex catalyst structure,unclear mechanism,low conversion,low reactant partial pressure,high energy consumption for recycle flow and product separation,and high CO₂ emission.The single-atom catalysts (SACs) show great application prospects in ethylene epoxidation reaction based on their outstanding advantages such as clear structure,clear mechanism,and controllable structure and performance,as well as their high atom utilization,high activity and selectivity.And the current relevant catalyst design strategies are mainly categorized into single-atom thermal catalysts and single-atom electrocatalysts.This review detailed the current research progress and challenges in this field,and gave some methods and suggestions to solve the dilemmas based on relevant research reports,including stability improvement of SACs,scale-up preparation techniques,design of novel SACs,and in-depth exploration of the mechanism as an aid.

M-MOF-74 (M=Zn,Co and Fe) materials synthesized using Zn,Co and Fe as central metals and 2,5-dihydroxyterephthalic acid as organic ligand were applied to the construction of vinyl acetate hydroformylation catalyst system.The morphology and structure of M-MOF-74 (M=Zn,Co and Fe) were characterized by XRD,SEM,N₂ adsorption-desorption and thermogravimetric analysis.Compared with Co-MOF-74 and Fe-MOF-74,the Zn-MOF-74 prepared with Zn as central metal had the largest specific surface area and pore volume.As for the catalytic activity of vinyl acetate hydroformylation reaction,M-MOF-74 (M=Zn,Co and Fe)/Co₂(CO)₈ prepared via a in-situ composite method showed significantly increased selectivity of branched-chain products comparing with Co₂(CO)₈.

The utilization of pyrolysis C₅ has become an important indicator for making full use of petroleum resources and improving the economic benefits of ethylene production.The presence of sulfide seriously affects the quality and utilization of C₅ products,and the key bottleneck of clean and efficient use of C₅ to produce high value-added products is the removal of sulfides.At present,the cracking C₅ desulfurization technology mainly includes catalytic hydrogenation,alkylation,oxidation,adsorption desulfurization,etc,and the research progress and existing problems of each technology are discussed,and the adsorption desulfurization technology is focused on on this basis.The research progress of activated carbon,molecular sieve and metal oxide adsorbents is introduced in detail,especially molecular sieve adsorbents will become the focus of future research on C₅ adsorption and desulfurization due to their excellent performance,mild operating conditions and simple regeneration.

Using Al₂O₃ as the support,RS-180 catalyst was prepared via the impregnation method and characterized by XRD,SEM,and mercury intrusion porosimetry to evaluate its performance in ethylene epoxidation to produce ethylene oxide.Results showed that α-Al₂O₃ exhibited a lamellar morphology with an innovative “interlocking” structure,enhancing the dispersion of silver nanoparticles.The catalyst achieved an ethylene oxide selectivity of 88% after 700 h of operation,with a stable upward trend,reaching 89% after 900 h,maintaining consistent performance.This provides reliable technical support for efficient ethylene oxide production and the stable development of downstream industries,promising to drive optimization and upgrading of the ethylene oxide industrial chain.

By adding silane reagent to intervene in the crystallization process of TS-1,the directional aggregation of nanocrystalline grains was achieved,and thus continuous and dense titanium-silicon molecular sieve membranes were prepared by bridging on micrometer-sized spherical carriers.Its structure was characterized by various analytical methods(SEM,XRD,FT-IR and UV-Vis),and its catalytic activity for the direct epoxidation reaction of chloropropene was examined.The experimental results showed that the TS-1 titanium-silicon molecular sieve spherical membranes prepared by the bridging method had higher homogeneity and densification,which improved the stability of the membrane layer during the epoxidation reaction.The selectivity of chloropropylene oxide,the yield of chloropropylene oxide,the conversion of H₂O₂,and the effective utilization efficiency of H₂O₂ reached 95.61%,86.93%,97.54%,and 93.21%,respectively.And there was no obvious decrease in the reaction activity after three cycle experiments.The TS-1 titanium-silicon molecular sieve membrane prepared by the bridging method is easy to be recycled and can be reused while maintaining its catalytic performance.

Beta zeolite were synthesized by the crystal-template agent hydrothermal method and modified by impregnation with rare earth metal Ce and transition metal Cr.The performance of their catalytic synthesis of ethyl levulonate(EL) was investigated.The results showed that the total acid content of the modified samples increased significantly.Under the conditions of n(acid)∶n(alcohol)=2∶3,temperature 150 ℃,catalyst amount of 6% by mass of acetopropionic acid,stirring rate 200 r·min^-1 and reaction for 5 h,the esterification efficiencies of Hβ-7%Ce and Hβ-3%Cr were better than those before modification,and the EL yields were 96.93% and 97.69%,respectively,while also demonstrating excellent regeneration performance.

Due to its unique electronic structure,palladium is widely used as an efficient catalyst in various fields such as chemical engineering,environment,and energy when loaded on different carriers.The catalyst itself does not change before and after use,but in practical applications,its activity severely declines due to poisoning,coverage,shedding,agglomeration,phase transformation,aging,and fragmentation.As a result,palladium-based catalysts can only be recycled and reprocessed into new catalysts.Although there are relatively mature recycling processes for these spent supported palladium-based catalysts,from the perspectives of environmental protection and economy,it is urgent to develop new green,economic,and efficient recycling processes.Starting from different carrier types,this paper reviews several recycling processes of palladium catalysts supported on various carriers,systematically analyzes and compares the advantages and limitations of various catalyst recycling processes,and looks forward to their future development.

Using waste lubricating oil as the feedstock,the effects of reaction temperatures on the hydroconversion characteristics,product distributions and properties were investigated with oil-soluble Mo-based catalysts and solid Fe-based catalysts.The results showed that the hydroconversion products of waste lubricating oil with reaction temperature are similar under two different catalysts.As the reaction temperature increased,the heavy oil conversion in waste lubricating oil significantly improved,primarily generating C₆-C₁₂ naphtha fractions and C₁₂-C₂₅ diesel fractions.At a reaction temperature of 450 ℃,the heavy oil was completely converted,with the combined yield of light oil reaching 92.35%.The content of impurity elements S,N,and O in the liquid products significantly decreased,while the H/C atomic ratio increased.The content of aliphatic hydrocarbons decreased,and the content of aromatic hydrocarbons slightly increased.Additionally,macromolecular hydrocarbons underwent polycondensation reactions on the surface of the solid products,forming micron to submicron spherical particles.

The catalyst replacement process of the 1.8 Mt·a^-1 Johnson Matthey large-scale Davy process methanol synthesis plant at Yulin Chemical Industry Co.,Ltd.,National Energy Group is described.The causes of the problems encountered in the process of system gas replacement,catalyst passivation,unloading,cleaning and loading are analysed,and optimisation measures and suggestions are put forward based on the field application,so as to reasonably avoid the risks of the various processes and to ensure the resistance drop of the synthesis tower at start-up is up to the standard.The proposed optimisation measures have been implemented in several plants of the same class,such as Yulin Chemical Co.,Ltd.,Xinjiang Chemical Co.,Ltd.,Baotou Chemical Co.,Ltd.,which can solve most of the problems during catalyst changeover,and provide a certain reference for domestic plants of the same class.

Propane dehydrogenation (PDH) technology is a crucial pathway for propylene production,but its catalysts are prone to deactivation due to carbon deposition,resulting in performance decline.This study focuses on the moving-bed PDH process,investigating the effects of modulating the pore structure and mechanical strength of the support on catalyst performance.Alumina-based supports (RS-1 to RS-4) were prepared using different pore-enlarging agents (PET-1000,PET-5000,and PVP),and a series of catalysts (RSC-1 to RSC-4) were synthesized by loading Pt-based active components via the equal-volume co-impregnation method.Nitrogen adsorption-desorption and strength tests revealed that the addition of pore-enlarging agents significantly increased the support pore size (from 10.9 nm to 24.5 nm),and the introduction of PVP mitigated the strength reduction caused by pore enlargement by enhancing particle binding forces.Catalyst performance was evaluated under conditions of 600-620 ℃,atmospheric pressure,and an H₂/C₃H₈ molar ratio of 0.5.The results showed that catalysts RSC-3 and RSC-4,prepared with large-pore supports,exhibited reduced carbon deposition due to optimized mass transfer processes,leading to significantly lower decay rates in conversion and selectivity,as well as superior stability compared to the small-pore catalyst (RSC-1).This study demonstrates that synergistic regulation of pore size expansion and mechanical strength can effectively enhance the carbon resistance and service life of PDH catalyst,providing key optimization direction for industrial catalyst design.Future research will focus on further optimizing the synergistic effects of additives and regeneration performance.

For improving the catalytic performance of Cu-based catalyst in CO₂ hydrogenation to methanol,the conventional Cu/Zn/Al catalyst,HCT-Cu/Zn/Al catalyst with hydrotalcite as precursor and HCT-Cu/Zn/Al/Mg catalyst were prepared by co-precipitation method.The effects of hydrotalcite precursors and MgO additives on copper species dispersion,copper specific surface area,catalyst basic site,carbon dioxide hydrogenation activity and stability were investigated.Through SEM,N₂O-TPD,H₂-TPR,CO₂-TPD and TEM characterization,it was found that the preparation of catalyst with hydrotalcite as the precursor system could promote the dispersion of copper species,increase the specific surface area of copper,and increase the strong alkaline sites of the catalyst surface.More importantly,the limiting effect of hydrotalcite could inhibit the sintering of copper species and improve the stability of the catalyst.In addition,MgO additive could further increase the specific surface area of copper,increase the strong alkaline sites on the catalyst surface,and inhibit the sintering of copper species.HCT-Cu/Zn/Al/Mg catalyst with hydrotalcite as precursor was used under the conditions of reaction temperature 250 ℃,reaction pressure 5 MPa,V(H₂)∶V(CO₂)=3∶1 and space velocity (GHSV)=10 000 mL·(g·h)^-1.The methanol spatio-temporal yield was as high as 0.57 g·(g·h)^-1,and methanol spatio-temporal yield was still 0.53 g·(g·h)^-1 after reaction for 50 h,showing good stability.

Isooctyl glycidyl ether was synthesized using liquid-solid phase transfer catalysis with isooctanol and epichlorohydrin as raw materials,quaternary ammonium salt as catalyst,and sodium hydroxide as acid binding agent.The effects of different catalyst,catalyst addition amount,reaction temperature,feed ratio,and reaction time on the product yield were investigated.Finally,the optimal etherification process parameters were finally determined based on orthogonal experimental design.The results showed that the optimal process parameters were as follows:catalyst addition amount of 8 g,feed ratio of 1∶1.2∶1.5 (1 mol of isooctanol,1.2 mol of epichlorohydrin,and 1.5 mol of sodium hydroxide),reaction temperature of 30 ℃,and reaction time of 7 h.When the acid binding agent was added in batches,the average yield of the product isooctyl glycidyl ether can reached 87.40%,and the purity reached 99.08%.

Although the removal technologies for single pollutants such as nitrogen oxides(NO_x) and chlorobenzene have become relatively mature,research on their synergistic removal remains scarce.This paper reviews the catalytic removal technologies of NO_x and chlorobenzene,with particular emphasis on the significance of synergistic catalytic technology in enhancing removal efficiency,reducing energy consumption and costs,providing a theoretical basis for the development of new and highly efficient catalysts.The influence of different metal oxides on catalyst performance is further discussed in detail.Finally,it was emphasized that future research needs to achieve breakthroughs in enhancing the performance,stability and selectivity of by-products of catalysts,and develop more efficient,economical and environmentally friendly pollution control technologies.

A series of catalysts with different metal and support were synthesized by chemical fluid deposition (CFD) method using supercritical CO₂ as solvent.In this work,hydrodeoxygenation of 2-methoxyl-4-allyl phenol was applied for investigating the performance of different catalysts.The effect of support (SBA-15, SO₄^2-/ZrO₂,HY) and content of different metal (Pd,Pt) on conversion and selectivity were investigated.While the effects of reaction condition on the conversion of reactant and selectivity of product were also evaluated.It was shown that the conversion of 2-methoxyl-4-allyl phenol and selectivity of high carbon number aromatic hydrocarbons could reach 98.0% and 94.2% respectively when SO₄^2-/ZrO₂ was support,m(Pd)∶m(Pt)=3∶1,total mass fraction of 3%,reaction temperature was 300 ℃.

Microflower-structured MoS₂ catalysts,both pure and doped with transition metals (Fe or Mn),were successfully synthesized via a one-step hydrothermal method for the hydrogen evolution reaction (HER).The morphology,composition and structure of the material were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD),and its hydrogen evolution performance during water electrolysis was studied.Results confirm the successful incorporation of Fe or Mn atoms into the MoS₂ lattice.At a current density of 10 mA/cm²,the Fe-doped catalyst (Fe-MoS₂-1∶10) exhibited the HER overpotential of 482 mV and the Tafel slope of 148 mV/dec,which were lower than those of pure MoS₂,demonstrating excellent electrocatalytic hydrogen evolution performance.Notably,the Mn-doped catalyst (Mn-MoS₂) achieved the lowest Tafel slope of 101 mV/dec,indicating the most favorable HER kinetics.

In the context of global climate change,carbon capture, utilization and storage (CCUS) technology has received widespread attention as a key technology for reducing greenhouse gas CO₂ emissions and achieving the “dual carbon” goal.The operating cost of CO₂ capture technology accounts for 70% of the total CCUS cost and is the core of CCUS technology.The PCET (proton-coupled electron transfer) reaction mechanism,as a crucial reaction pathway in the fields of energy conversion and environmental protection,has demonstrated significant application potential in CO₂ capture technology.This article introduces the mechanism of PCET,summarizes the latest research progress of PCET application in electrocatalytic CO₂ capture,deeply analyzes the advantages of related technologies,and further looks forward to future development directions,providing theoretical references for CO₂ capture.

Excessive use of pesticides in agriculture to protect crops has led to widespread pesticide residues in soil, air, water, the blood and urine of living organisms, posing a significant threat to ecosystems and human well-being.To address this issue, the advanced oxidation processes (AOP) utilizing semiconductor photocatalysis to degrade pollutants into simpler compounds has become one of the promising methods.Photocatalysts play a crucial role in this process.Among them, zinc oxide (ZnO) has received widespread attention due to its excellent photocatalytic performance, cost-effectiveness, and environmental friendliness.The research status of eliminating organophosphorus pesticides widely used in agriculture from the environment by using semiconductor photocatalysis is mainly introduced.It provides an overview of water pollution caused by organophosphorus pesticides, their occurrence, classification, and introduces the development of doped ZnO photocatalysis.The main emphasis was on the use of ZnO based composite materials for the degradation of organophosphorus pesticides, and the effects of operating parameters such as catalyst dosage, pesticide concentration, pH and reaction temperature on the photocatalytic degradation process were explore.