SCR (Selective Catalytic Reduction) is currently the mainstream nitrogen oxide (NO_x) removal technology.Commercial catalysts operate at high temperatures,typically between (250-350) ℃,making them difficult to apply in low flue gas temperatures.We have modified a monolithic V-series denitrification catalyst,which exhibits excellent denitrification performance at low temperatures.This article studied the low-temperature activity of the modified V-series NH₃-SCR denitrification catalyst and successfully applied it under actual flue gas conditions of (120-160) ℃.The stable operation time of the pilot test exceeded 10 months,and the outlet NO_x concentration could always meet the emission standards.The performance of the catalyst after operation was analyzed and explored.The pilot test verified the feasibility of the technical route and the reliability of the catalyst,and completed the demonstration work of the industrial plan,which has the conditions to carry out demonstration projects.

The large amount of waste plastics produced by human activities has brought serious pollution to the air,soil and sea in all fields.And even microplastics in the environment enter the human body through biological circulation,causing great harm to human health.According to the current recycling status of waste plastics,the research progress on several chemical recycling methods and new recycling processes for chemical recycling of waste plastics with sustainable development prospects were reviewed, mainly including solvolysis,hydrogenolysis,photocatalytic degradation.The catalytic degradation methods adapted to different types of waste plastics and the important role of various catalysts in the catalytic degradation reaction were summarized.And the catalytic efficiency of the main current catalysts was compared to provides a theoretical basis for the selection of effective catalysts and methods for the efficient degradation of waste plastics.

Cerium dioxide (CeO₂) has excellent oxygen storage and release properties,oxygen mobility and abundant surface defects,and is easy to form metal-carrier strong interaction to stabilize precious metal particles.As an active component and carrier catalyst,CeO₂ is widely used in the oxidation elimination of environmental pollutants.Single CeO₂ has poor catalytic activity and thermal stability.Loading,doping and composite methods are often used to regulate the surface interface properties and microstructure to improve its catalytic performance and thermal stability.In this paper,the surface interface regulation strategies and catalytic mechanisms of cerium based catalysts in recent years were reviewed,and the effects of interface effects and interionic synergies on catalytic oxidation of small molecular pollutants were analyzed.

Ethyl ether is a colorless,flammable,and uniquely odorous liquid with a wide range of uses.The dehydration of ethanol to ethyl ether has a wide source of raw materials and low price,but H₂SO₄ solution is usually used for catalysis,which leads to serious corrosion of equipment.The use of solid acid catalyst has low cost and low corrosion.The reaction mechanism of ethanol dehydration to ethyl ether was reviewed.The research progress of solid acid catalysts,including alumina catalyst,zeolite catalyst and transition metal oxide catalyst,was summarized,and their development direction was prospected.

As an important green energy,hydrogen energy is an important guarantee to achieve carbon neutrality and carbon peak.Anion exchange membrane electrolytic cell combines the advantages of alkaline electrolytic cell and proton exchange membrane electrolytic cell,and can use non-precious metal catalyst combined with renewable energy,which is expected to break the bottleneck of high cost of green hydrogen preparation.In this paper,the recent research progress on the stability of non-noble metal catalysts for water electrolysis by AEM is reviewed.The dissolution and degradation behavior of catalyst metals are discussed,and the mechanism of oxygen evolution reaction on catalysts is emphasized.

Proton exchange membrane fuel cell is a high-efficiency power supply device using hydrogen energy,and its cathode iron-nitrogen-carbon(Fe-N-C) catalyst can effectively solve the problems such as high cost and difficult recovery of commercial platinum-based catalysts,and has broad application prospects.The activity and stability of Fe-N-C catalyst is superior to that of commercial Pt/C catalyst.The research background of Fe-N-C catalyst is briefly introduced.The influence of composition of Fe-N-C catalyst on performance in recent years is introduced from the aspects of precursor,support and auxiliary,and its development direction is prospected.

The study of carbon dioxide(CO₂) hydrogenation to methanol is significant for China to alleviate the energy pressure and achieve carbon peaking and carbon neutrality goals.In this reaction,the design and optimization of the catalyst are the essential elements in determining the CO₂ conversion and methanol selectivity.Alloy catalysts show extraordinary potential in promoting CO₂ activation and hydrogenation process due to their unique electronic structure and geometrical configuration.This review comprehensively surveys the advancements in solid-solution alloys and intermetallics,particularly Cu-based,In-based,Ga-based,and other emerging alloy systems,for heterogeneous catalysis of CO₂ hydrogenation to methanol.This paper also analyzes the current research strategies and ideas.It looks forward to the potential future directions and applications of alloy catalysts,aiming to provide valuable insights for researchers in related fields.

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.

Exploiting the natural abundance and cost-effectiveness of clay minerals,particularly kaolinite,offers vast potential in the realm of functional catalyst carrier materials.Their abundance of surface groups and active hydroxyl moieties act as a catalytic hotbed.The unique lamellar structure of kaolinite further enhances its functionality,allowing for tailored modifications.This review delves into the extensive applications of kaolinite-based composite catalytic materials across diverse catalytic fields,encompassing photocatalysis,petroleum catalytic cracking,electrocatalysis,and thermal catalysis.Lastly,the review concludes with a prognosis on the evolving role of kaolinite-based catalytic materials in environmental purification.

Proton exchange membrane fuel cell,as a new type of energy conversion device with high energy density,friendly environment,fast starting speed rate at room temperature and long life,is the first choice of automobile power new energy battery.The catalyst is the key factor affecting the activation polarization of proton exchange membrane fuel cells.In this study,mass fraction of 50%Pt/C catalyst was prepared by using acetophenone semicarbazone as modifier and tetrammineplatinum chloride as active component.The preferred catalyst has a specific mass activity of 217.64 mA·mg^-1 and an electrochemical active area of 87.63 m²·g^-1 for electrochemical activity test.After 30 000 cycles of durability test,the specific mass activity and the electrochemical active area have only declined by 11.57% and 15.63%,respectively.

Polyoxometalates(POMs),as a type of multinuclear coordination polymer,have found extensive applications in catalysis,adsorption,and electrochemistry due to their unique structures and excellent physicochemical properties.However,the solubility of POMs in polar solvents has limited their application scope.To address this issue,researchers have developed POM-based composites.This review summarizes the latest research progress of POMs-based composites in the fields of biomass conversion,pollutant treatment,and electrochemistry.Studies have shown that these composites exhibit significant advantages in enhancing catalyst stability,promoting the transformation of biomass macromolecules,improving the efficiency of wastewater treatment and gas purification,and improving electrochemical performance.These achievements not only overcome the problem of POMs’ solubility but also provide new ideas and directions for technological innovation and applications in related fields.

CeO₂-ZrO₂ mixed oxides are considered as one of the key components in the three-way catalysts for automotive exhaust purification.The increasingly strict emission regulations have brought much higher requitements regarding the thermal stability of CeO₂-ZrO₂ mixed oxides.In this work,CeO₂-ZrO₂ with excellent thermal stability were synthesized through co-precipitation method.The effect of synthesizing parameters including doping element,precursors,washing methods as well as ageing conditions on the specific surface area and thermal stability of the CeO₂-ZrO₂ samples were investigated.Results shown that CeO₂/ZrO₂/La₂O₃/Y₂O₃/Nd₂O₃ (CZLYN) samples prepared by using La-Y-Nd co-doping as the modified component,Ce(NH₄)₂(NO₃)₆ containing Ce⁴⁺ as the cerium precursor,washed with ethanol and aged in an ethanol environment for 12 h exhibited the optimal specific surface area and thermal stability.The specific surface can still maintain at 38 m²·g^-1 after 12 h thermal ageing at 1 050 ℃ using muffle furnace.The optimized CZLYN sample was further characterized and compared with one of the commercial CeO₂-ZrO₂ powder.Results showed that these two samples presented similar physical structure,grain size,pore size distribution and surface micro-morphology while the specific surface area of the optimized CZLYN sample was increased by about 60%.After thermal ageing at 1 050 ℃ using muffle furnace,the optimized CZLYN sample presented about 20% increase in the specific surface area of compared to the commercial CeO₂-ZrO₂ powder;after hydrothermal ageing,the optimized CZLYN samples still showed slightly higher specific surface area and about 30% increase in dynamic ox oxygen storage/release capacity,indicating its superior thermal stability.

Due to the unique pore structure and excellent performance,porous ceramics have broad application in moisture sensitivity,gas sensitivity,filtration,sound absorption,heat insulation and catalytic carrier,especially in the field of environmental catalysis.Compared with catalyst powder alone,the supported porous ceramic catalysts have the advantages of large specific surface area,high catalytic activity,easy recovery,high carrier strength and corrosion resistance,which has become a research focus in recent years.The research progress of porous ceramics in catalytic treatment of volatile organic compounds,automobile exhaust gas,flue gas,printing and dyeing wastewater,and other organic wastewater degradation was reviewed,and the problems and development trends were prospected.

Efficient and acid stable oxygen evolution reaction (OER) catalysts are crucial for the large-scale application of proton exchange membrane (PEM) electrolysis technology coupled with renewable energy to produce green hydrogen.In this work,a series of iridium cobalt oxide catalysts with different iridium contents are prepared through a simple one-step molten salt thermal decomposition method followd by optimization.Electrochemical tests have shown that,compared with the rapid deactivation of cobalt oxide,the optimzied Ir_0.13Co_0.87O_x catalyst has an overpotential of only 270 mV at a current density of 50 mA·cm^-2,and can stably work for more than 50 h at a high current density of 100 mA·cm^-2.The study of structure-activity relationship shows that the uniform doping of iridium in the bulk lattice of cobalt oxide improves the stability of the catalyst and greatly reduces the impedance of charge transfer.At the same time,Ir replaces some of the tetrahedral coordinated Co²⁺ in Co₃O₄ with an average valence state slightly higher than +4,resulting in the catalyst surface prevails stable and high valence Ir⁴⁺ and Co³⁺ both in tetrahedral and octahedral form,hence greatly improving the activity and stability of the catalyst.This work reveals that the coordination structure and valence state of Ir in doped transition metal oxides play a crucial role in improving the OER activity and stability,hence provides a new solution for the development of efficient and stable low iridium based OER electrocatalysts working in acidic media.

Metal nanoclusters have attracted widespread attention in electronic structure,optics,electronics,magnetism,catalysis and other fields due to their unique quantum size effects and electron confinement effects.The surface protective ligands not only play the role of coordination protection,but also have important effects on the structure and physicochemical properties of metal nanoclusters.In addition to the most common protective ligands such as sulfur and phosphine,metal nanoclusters anchored by organic carbon (organometallic nanoclusters) have become a focus of research for researcher due to their various coordination modes,strong reaction and catalytic activity.In this paper,organic carbon ligands are mainly divided into N-heterocyclic carbene ligands with single coordination sites and conjugated aromatic rings or olefin and alkynyl ligands with multiple coordination sites.The synthesis methods,structures and catalytic applications of organometallic nanoclusters anchored by organic carbon with definite structure are summarized,which has providing references for the further study of organic metal clusters.

As a new large-scale energy storage technology,all vanadium redox flow battery has the advantages of high safety,adjustable power and capacity,long life,recyclable electrolyte and environment-friendly,but the solubility of vanadium ions in electrolytes is poor,which limits its large-scale application.The preparation of high concentration and high stability electrolyte is one of the key technologies of all vanadium redox flow battery.In this paper,the preparation method,concentration analysis and performance optimization of the electrolyte are introduced.

Residual oil hydrogenation technology is an important means of light utilization of heavy oil.Under the background of increasingly heavy and inferior heavy oil raw materials,residuum hydrogenation technology is mainly faced with high cost,short plant operation cycle,equipment engineering and process operation difficulties.The development and application of fixed bed,boiling bed,slurry bed and combined residual oil hydrogenation technology are reviewed.Upflow and combined residuum hydrogenation technology may become the mainstream technologies in the future development to meet the needs of deep conversion of heavy oil,improve liquid yield and clean production,and assist the product structure transformation of refining enterprises to improve the market adaptability of refineries.

The hydrogenation of furfural and its derivatives to pentanediol has been widely recognized as a sustainable and green process.In this selective hydrogenation process,the design of highly active and selective catalysts plays a critical role.In this paper,the mechanism of metal-base and metal-acid catalytic reaction is introduced in detail according to acid-base properties of the support.This review describes the latest research progress of catalysts in the hydrogenation of furfural and its derivatives to pentanediol from catalyst support type point of view.And it discusses the effect of strong metal-support interaction between different carriers and metal on catalytic performance.At the same time,the current problems of such as the unclear catalytic mechanism and the inability to large scale production are pointed,and the adjustment of metal dispersion and acid-base properties of the support to further improve the catalytic performance should be the key points for future research.

A series of alumina precursors were prepared by nitric acid method using NaAlO₂ as raw material,and α-Al₂O₃ was obtained by calcination at high temperature.The supported palladium catalyst was prepared by incipient impregnation and their performance of CO oxidation coupling to dimethyl oxalate was evaluated on a fixed bed reactor.The texture and surface properties of the samples was characterized by XRD,BET,SEM,NH₃-TPD and H₂-TPR.The results showed that the precursor was prepared at gelation temperature of 55 ℃,pH of 7.0,and NaAlO₂ concentration of 0.8 mol·L^-1.The α-Al₂O₃ carrier prepared by the precursor calcined at 1 200 ℃ has high specific surface area,suitable surface acidity,suitable pore size distribution and large porosity.On a palladium-based catalyst prepared with this support,the conversion rate of methyl nitrite (MN) was 87.4% and the selectivity of dimethyl oxalate (DMO) was 96.1% at 3 000 h^-1,130 ℃,and CO/MN ratio of 4:1.

Ni/SiO₂ catalyst was prepared by traditional co-precipitation using sodium silicate and silica sol as silicon sources,and nickel nitrate as nickel source.The study showed that modification with ethylene glycol effectively reduced the condensation of hydroxyl groups (Ni-O-Ni) during drying or roasting and therefore reduced the agglomeration of Ni active components.The catalyst modified with ethylene glycol had the characteristics of large specific surface area,large pore structure,the stronger interaction force between the Ni active metal and the carrier.The finer particle size of Ni metal,the higher dispersion of the active components and more active sites were exposed as shown by the characterization results of N₂ adsorption-desorption,H₂-TPR,XRD,H₂-TPD and SEM.Hydrogenation performance of C₅ petroleum resin showed that the performance of catalyst modified with ethylene glycol was significantly improved.

Magnetic nanocomposite photocatalysts have gained significant attention in the field of photocatalysis due to their efficient catalytic activity,recyclability,and stability.This article provides a comprehensive review of the preparation methods for magnetic nanocomposite photocatalysts,including the co-precipitation method,sol-gel method,hydrothermal/solvothermal synthesis method,and chemical vapor deposition method.The focus is on analyzing the impact of doped type,core-shell structure type,and graphene oxide on the photocatalytic performance of magnetic composite nano-photocatalysts.The article also discusses the degradation mechanism of pollutants by composite photocatalysts and their application in wastewater treatment.Furthermore,it proposes improvement measures for the catalyst synthesis process and highlights potential future research directions for magnetic nanocomposite photocatalysts.

Methylphenol is an important fine chemical intermediate,widely used in new materials,medicine,pesticides,spices,additives and other fields.The alkylation reaction of phenol and methanol has the advantages of high efficiency,environmental friendliness and high product purity,which is the most economical production process of methyl phenol.The reaction is divided into liquid phase and gas phase.The liquid phase reaction is mainly carried out in the kettle reactor,while the gas phase reaction is mainly carried out in the fixed bed reactor.The catalyst can be divided into oxide and molecular sieve systems.The multi-component composite oxide catalyst has ideal reaction performance and high ortho-selectivity,but the reaction temperature is high.Molecular sieve catalyst has certain advantages in shape selection,but it is easy to accumulate carbon and deactivate.The acid-alkalinity of the catalyst is an important index,and their synergistic effect directly affects the selectivity of C-alkylation,otherwise it will increase the selectivity of side reactions such as O-alkylation products.In order to meet the demand for high-performance products in the fields of new materials and electronic chemicals,it is still necessary to further develop high-performance phenol methylation catalysts to improve the competitiveness of related industries.

As the third largest greenhouse gas followed by CO₂ and CH₄,N₂O has been increasing year by year due to its inevitable generation and emission in the processes of ammonia oxidation in nitric acid production,SCR purification of NO_x,and ammonia combustion.Therefore,the purification and elimination of N₂O are particularly crucial.Direct catalytic decomposition has emerged as one of the most promising methods for reducing N₂O emissions due to its high efficiency and no secondary pollution.This article first provides a detailed review of the research progress of N₂O decomposition catalysts in recent years,reviewing the practical application and future development trends of N₂O high-temperature decomposition catalysts (two-stage catalysts) in the nitric acid production,focusing on the research trends of three major types of N₂O low-temperature decomposition catalysts,such as precious metal catalysts,Co-based oxide catalysts,and Co or Fe-based molecular sieve catalysts,and summarizing the advantages and disadvantages of these catalysts.In addition,a simple discussion is provided on the decomposition mechanism of N₂O on typical Co and Fe-based catalysts.Selective catalytic reduction as one of the main technological routes for elimination of N₂O is also compared using different reducing agents such as CO,H₂,alkanes,etc.Finally,it identifies existing issues in current catalytic systems and outlines future prospects for N₂O catalytic decomposition.

The hydrogenation of unsaturated compound is an important process of chemical processing that is widely used in the fields of oil refining,medicine,flavor,and so on.Heterogeneous catalytic reactions with porous organic polymers(POPs) as catalyst supporters possess the advantages of recyclable catalysts and mild reaction condition.The recent progress of POPs in olefins hydrogenation,alkyne hydrogenation,aldehyde-ketone hydrogenation,aromatic ring substitution hydrogenation and CO₂ hydrogenation was summ-arized.The challenges and future development directions were also put forward.

1,1,2-Trifluoroethylene (HFO-1123,TrFE),as a novel hydrofluoroolefin (HFO) refrigerant,possesses an Ozone Depletion Potential (ODP) of zero and a 100-year Global Warming Potential (GWP₁₀₀) value of merely 0.005,rendering it environmentally benign and suitable for diverse applications.This attribute has garnered substantial attention from scholars and experts worldwide.Notably,the catalytic cleavage of 1,1,1,2-tetrafluoroethane (HFC-134a) to yield HFO-1123 not only mitigates the greenhouse impact associated with HFC-134a, but also addresses the issue of its surplus production capacity.This article systematically reviews recent domestic and international advancements in the research on the dehydrofluorination of HFC-134a to synthesize HFO-1123,encompassing the categorization,discussion,and summarization of catalyst types,preparation methods,and diluent gases.The aim is to provide a comprehensive reference for future investigations into the dehydrofluorination of HFC-134a for the production of HFO-1123.

Based on the proposal of “dual carbon” goal,and the current energy structure of “limited gas and oil,but relatively abundant coal resources”,the development of directly catalyzing synthesis gas for the production of higher alcohols conforms to the major strategic of China.The research and utility of the catalysts is the key and difficult point in the development of this technology.Thus,this article provides a review on the synthesis gas to higher alcohols reaction and its catalysts.The existing production processes,catalyst types,and factors affecting catalyst performance are summarized systematically to explore the direction for direct synthesis of higher alcohols from syngas in the future.

Preparing phosphide electrocatalysts with both excellent intrinsic activity and abundant active sites toward efficient hydrogen production is beneficial for the realization of the hydrogen society.In this study,we utilized combined methods of electrochemical deposition and chemical vapor deposition to construct a cobalt phosphide-molybdenum phosphide on an electrospun carbon nanofibers substrate as monolithic electrocatalyst (Mo-Co-P/CNFs) with excellent hydrogen evolution performance.The Mo-Co-P/CNFs catalyst which can be directly used as a working electrode,not only exhibits improved intrinsic activity but also has highly abundant active sites,realizing a current density of 100 mA·cm^-2 under overvoltage of only 70 mV in a 1 M KOH electrolyte.This study is expected to offer useful references for the preparation of high-performance phosphide catalysts

Methane anaerobic aromatization (MDA) is considered as a promising industrial pathway for methane utilization,offering a single-step conversion of methane into high-value products like benzene and toluene.However,the formidable energy barrier posed by the methane C—H bond presents a challenge for catalysts to activate methane efficiently at low temperatures.Moreover,catalysts often suffer from deactivation due to carbon deposition during high-temperature MDA reactions,which hampers the widespread industrial adoption of MDA.To address these challenges,this study explored the preparation of catalysts by mixing Mo/HZSM-5 with a hydrogen storage alloy (CN-3) for MDA.This approach synergistically couples methane dehydrogenation with dehydrogenation process to facilitate methane activation and enhance benzene production even at low temperatures.The performance of the catalyst was optimized by varying the preparation methods of Mo/HZSM-5 and CN-3 (e.g., mechanical grinding,ball milling, or impregnation) along with adjusting Mo content.The results indicate that the mechanical mixing method proves superior in maintaining the original morphology and performance of CN-3 alloy and Mo/HZSM-5 samples,thereby resulting in optimal catalytic activity of prepared catalysts for MDA.With this method,the addition of CN-3 increased the methane conversion in the MDA reaction from 13.5 % to 22.9 %,and the benzene production rate increased from 28.7 μmol·(min·g)^-1 to 52.3 μmol·(min·g)^-1.

The effect of catalyst preactivation on the hydroformylation of 1-octene in homogeneous Rh/diphosphine catalyst system has been investigated in terms of preactivation temperature,preactivation time and preactivation atmosphere.The results show that the preactivated catalyst is beneficial to improve the conversion and selectivity and thus increase the aldehyde yields.However,when the preactivation temperature exceeded 70 ℃ and the preactivation time was 20 min,the aldehyde selectivity would decrease.In addition,preactivation in the syngas atmosphere is conducive to the formation of catalyst active centers.

The commercial application of self-developed THFS-2 catalyst in a 200,000 TPY deep catalytic cracking (DCC) unit in Yulin Refinery of Yanchang Oil Group is introduced.The physicochemical structure of THFS-2 hydrogenation catalyst was characterized by BET,XRD and H₂-TPR,and the reason of its high hydrogenation activity was revealed.The pilot experiment and the industrial application show that the THFS-2 hydrofining catalyst has excellent activity and stability in the treatment of deep catalytic cracking (DCC) gasoline with high sulfur,high nitrogen,high olefin,high diolefin and high aromatics.The product with mass fraction of sulfur and nitrogen less than 1.0 μg·g^-1 and value of bromine less than 0.5 gBr·(100g)^-1 can be produced.All the indexes are better than the requirements of aromatics extraction feed.Compared with the previous cycle reference agent,the average temperature of the reactor is reduced,the reaction temperature rise is stable and controllable,and the device can run stably for a long period.

In this paper,hydrothermal treatment of Zn-based Silicalite-1 (S-1) catalyst at different temperatures was performed to explore the effect of high-temperature hydrothermal treatment on the catalyst and its propane direct dehydrogenation (PDH) performance.After high-temperature hydrothermal treatment,the propane conversion of the catalyst decreased from 68.49% to 1.42%.The samples were characterized by XRD,SEM,TEM,N₂ physisorption,DR UV-vis,XPS,NH₃-TPD,and Py-IR techniques.The results indicate that ZnO forms Zn-O-Si bonds with the S-1 molecular sieve and high-temperature hydrothermal treatment disrupts the Zn-O-Si bonds,which results in the aggregation of ZnO particles and an increase in particle size.Simultaneously,the Lewis acid (L-acid) content decreases,leading to a decrease in the catalytic performance of the catalyst for the PDH reaction.

Catalytic transformations of syngas into high value chemicals is of great significance for improving the efficiency of carbon resource utilization.This review highlights the latest developments and challenges in direct synthesis of olefins and aromatics from syngas.The content covers the active site design,product distribution regulation,C—O activation and C—C coupling.In the future,the effective regulation of product selectivity can be realized by controlling the efficient synergy between activation of C—O and C—C coupling,and precise control of carbon chain termination behavior.

On the basis of ZrO₂ catalyst doped with Si and La,this article introduces the pore forming agent polymethyl methacrylate(PMMA) in different ways to regulate the acidity,alkalinity and pore properties of the catalyst,and improve the conversion and selectivity of the gas-phase selective dehydration of 1,4-butanediol(BDO) to prepare 3-buten-1-ol.Through X-ray diffraction(XRD) for phase analysis,and characterization results such as Fourier transform infrared spectroscopy(FT-IR),NH₃ temperature programmed adsorption(NH₃-TPD),and CO₂ temperature programmed adsorption(CO₂-TPD),it can be seen that the pore forming agent PMMA can significantly improve the dispersion of Si and La elements,thereby enhancing the acidity and alkalinity of the corresponding catalyst.At the same time,characterization results such as N₂ physical adsorption-desorption curves and scanning electron microscopy(SEM) showed that the pore forming agent PMMA changed the microstructure of the catalyst,improved its performance,especially ZrO₂-DPM catalyst,and ultimately achieved a conversion of 85.36% for 1,4-butanediol and a selectivity of 64.56% for 3-buten-1-ol.

Hematite photoanode was modified via Zr doping to improve photoelectrochemical water splitting efficiency.FeOOH precursor was synthesized by chemical bath method,followed by impregnation and high temperature annealing method to prepare Zr doped hematite phtoanode.The results of photoelectrochemical tests reveal that the photocurrent density of the Zr doped hematite photoanode is significantly increased compared with that of the pure hematite photoanode.The improvement of the photocurrent density is due to the enhanced charge separation and injection efficiency.The study of photoelectrochemical impedance spectroscopy further demonstrates that Zr doping can effectively reduce the surface charge recombination rate k_rec.Therefore,Zr doping can passivate the surface states existing in the surface of hematite photoanode,which will reduce the surface recombination of photogenerated charges and promote the separation of photogenerated charges.

Proton exchange membrane fuel cells have low fuel price,no chemical danger and no pollution,which is impossible to achieve by all other power sources at present.However,the hydrogen obtained by the traditional process contains about 1% CO,which is easy to “poison” the Pt catalyst of fuel cells.The selective oxidation method can effectively remove CO in hydrogen-rich gas and reduce the CO content.Perovskite-type composite oxides show good selective oxidation activity of CO due to their unique physical and chemical properties,which has become a research hotspot in this field.CuO/LaMnO₃ catalyst was prepared by coprecipitation-impregnation method for the preferential oxidation of CO in hydrogen rich environment.The effect of calcination temperature on the properties of the catalyst was investigated, and the structure of the catalyst was analyzed by XRD and TPR.

The Keggin-type phase transfer catalyst(C_nH_2n-4N)₃PW₄O₃₂ was synthesized with phosphotungstic acid and different quaternary ammonium salts in one step by solvent extraction of methylene chloride.The catalyst was characterized by FT-IR,UV-vis and Raman.Cat-1(5.5-15%) catalyst with good performance was selected for cyclopentene oxidation to prepare glutaraldehyde reaction.The optimal cond-itions were:tert-butanol as solvent,n(catalyst)∶n(cyclopentene)=0.004 8,reaction time 5 h,n(hydr-ogen peroxide)∶n(cyclopentene)=1.2,reaction temperature 40 ℃.The conversion rate of cyclopentene was 99.04%,the selectivity of glutaraldehyde was 75.11%,and the catalyst could still maintain high catalytic performance after 5 cycles of use.In the reaction,(PW₄O₃₂)^3- was transformed into soluble small molecule {PO₄[WO(O₂)O₂]₄}^3- under the action of oxygen atoms,and dissolved in the reaction system,and further reacted with H₂O₂ to produce reactive oxygen species W(O)₂ and catalyzed cyclopentene reaction.After the consumption of H₂O₂,the small molecule was re-polymerized and precipitated.

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.

The causes for the bed sludge formation of the low-temperature chloride removal adsorbent for reforming hydrogen were explored,and the influence of the hydroscopicity of the active component on its structure and mechanical strength were studied.Alumina-based chloride removal adsorbents and bimetallic oxide chloride removal adsorbents were successfully developed,and characterized using XRD,XRF and nitrogen adsorption methods.Catalyst performance was tested in a small-scale experimental apparatus.The experimental data show that the chloride removal adsorbents is comparable to similar foreign chloride removal adsorbents in terms of both structure and performance indexes.The two newly developed dechlorinating agents for low-temperature dechlorination of reforming hydrogen have good dechlorination accuracy,which can effectively solve the problems of short service life,increased resistance drop,and difficult unloading caused by bed mud and agglomeration during the use of dechlorinating agents.They can also effectively solve the problem of ammonium salt crystallization blockage in the rear system.

Four types of alumina carriers were obtained with pseudo-boehmite as the main raw material through different treatment methods,and further supported PtSnNa/Al₂O₃ dehydrogenation catalysts were prepared.The test results of XRD and N₂ adsorption demonstrate that the treatment process of pseudo-boehmite had a significant effect on the structural characteristics of alumina support.An alumina support with γ-Al₂O₃ crystal phase can be obtained by refluxing the pseudo-boehmite with ethanol solvent and subsequent calcining in a nitrogen atmosphere.This γ-Al₂O₃ support has a specific surface area of 248 m²·g^-1,a total pore volume of 0.89 mL·g^-1,an average pore size of 15.5 nm.However,the specific surface area,total pore volume,and average pore size of the alumina sample obtained by direct calcination in air are relatively small.Four PtSnNa/Al₂O₃ dehydrogenation catalysts were used for catalyzing the reaction of isobutane dehydrogenation to isobutene.The PtSnNa/Al₂O₃ catalyst made of alumina support with larger pore volume and pore size shows the optimal catalytic performance in isobutane dehydrogenation reaction.The average conversion of isobutane on this catalyst is as high as 47.2%,the average selectivity of isobutene is as high as 96.3%,and the lifetime of the catalyst exceeds 100 hours.The carbon-deposited catalyst after the reaction was investigated by thermal analysis method.The characterization results indicate that a smooth pore structure is conducive to the migration of intermediate species and the removal of reaction products,while improving the carbon capacity of the catalyst.