Water splitting is one of the most promising methods for hydrogen production currently.Due to the high cost and limited supply of commercial precious metal-based catalysts,the exploitation of low-cost electrocatalysts is essential to realise the industrialisation of electrocatalytic techniques.Transition metal phosphides have received much attention due to their unique physical-chemical properties and high catalytic activity,but the lack of electrical conductivity and active site density has limited their application in industrial hydrogen production.This review describes the mechanism of hydrogen evolution by electrolysis and the important role of transition metal phosphides firstly,then analyses different types of transition metal phosphides and ways to enhance their catalytic performance from four aspects:monometallic phosphides,bimetallic phosphides,modified metal phosphides and structurally modulated transition metal phosphides,and compares the currently common preparation methods of transition metal phosphides.Finally,it summarises the main strategies for improving catalytic performance and looks forward to the future opportunities and challenges of transition metal phosphides.We expect this review to contribute to the design,development and application of transition metal phosphide electrocatalysts.

Metal organic frameworks (MOFs),a new class of porous materials with high specific surface areas and tunable pore structures,have been received growing attention for fine chemical synthesis in recent years.However,the poor stability of MOFs restricts their application in many catalytic processes.MOFs-derived materials prepared with MOFs as precursor can inherit the structural advantages of MOFs,and also overcome the stability issue of MOFs,which expands the applications of MOFs in catalytic reaction.Herein,research progresses of MOFs derived materials in catalytic field,especially in hydrogenation and oxidation for fine chemical production are reviewed.Furthermore,the existing challenges and development prospects of MOFs derived materials using in catalytic field are also discussed.

The dehydrogenation of ethane in CO₂ has attracted much attention due to the advantages of more thermodynamic feasibility,higher ethane conversion and ethylene selectivity,inhibition of carbon accumulation,and can also alleviate the greenhouse effect,etc.In this review,recent research progress of Cr-based catalysts for dehydrogenation of ethane to ethylene in CO₂ were elaborated.The reaction mechanism of Cr-catalyst,effects of support modification,promoters and preparation methods on catalytic perf-ormance were introduced,and prospects as well as future applications of the catalysts were outlined.

Holocrystalline ZSM-5 zeolite catalyst was successfully prepared with ammonia as template in the system free of alkali metal or alkaline-earth metal addition.After crystallization,the residual ammonia in the crystallized mother liquor was recovered by flash evaporation technology,with a recovery efficiency up to 85%.The recycling of the recovered ammonia was further realized,and holocrystalline zeolite catalyst could be obtained after repeated recycling for three times.The characterization results indicate that by optimizing the synthesis formula,the holocrystalline ZSM-5 zeolite catalyst could be prepared under crystallization conditions of 170 ℃ and 6 hour,with regular crystal morphology,abundant intercrystalline pore,perfect active center state and high mechanical strength (108 N·cm^-1).In the gas-phase alkylation of dilute ethylene and benzene to ethylbenzene,the holocrystalline ZSM-5 zeolite catalyst shows excellent activity,selectivity,stability and regeneration performance.And the content of xylene,the key impurity in the reaction product,is only (350-400) μL·L^-1,fully meeting the industrial application requirements.

Polymethyl methacrylate (PMMA) and polystyrene (PS) colloidal crystal template agents were prepared by soap-free emulsion polymerization method,and the prepared template agents and the treated P123 were used as templates to prepare LaNiO₃ perovskite oxides,respectively.The effects of the template types on the crystal structure,surface morphology,reduction properties and pore size distribution of the LaNiO₃ perovskite were investigated by XRD,SEM and H₂-TPR.The results showed that the samples prepared by different kinds of template agents formed obvious perovskite oxide structures,and the pore size distribution was mainly mesoporous-mesoporous hierarchical pore structure,which affected the reduction performance and surface morphology of the samples due to the difference of pore size distribution and specific surface area.The LaNiO₃ perovskite oxides prepared when polymethyl methacrylate colloidal crystal were used as template agents had high specific surface area and good reduction performance.The single conversion of phenol reached 22.48% at 0.1 MPa,350 ℃ and hydrogen flowrate of 40 mL·min^-1.The direct deoxygenation reaction mainly occurred,and the products were mainly benzene.

ZnO nanoarrays were prepared by seedless layer low temperature solution method using zinc nitrate and ammonia as raw materials.The defective ZnO nanoarrays were further prepared by sodium borohydride reduction method.The structure and composition of the defective ZnO nanoarrays were analyzed by SEM,XRD,UV-Vis DRS and IR.The effects of sodium borohydride concentration,reduction reaction temperature and time on the photodegradation performance of defective ZnO nanoarrays were further discussed.The results show that the prepared ZnO nanoarrays are closely arranged on the surface of the stainless steel mesh,and the morphology of the defective ZnO nanoarrays is still hexagonal columnar,with a diameter of (0.5-1) μm.The photocatalytic experiments show that the performance of defective ZnO nanoarrays prepared in 1 M sodium borohydride solution,reduction reaction temperature 50 ℃ and reduction reaction time 12 h is best,and the degradation efficiency of methylene blue is as high as 95.9%,which is 44 percentage point higher than that of ZnO. In addition,defective ZnO nanoarrays also showed strong degradation performance for ofloxacin,norfloxacin and ciprofloxacin.

Five Cu-based catalysts were prepared by mixing method,including CuAlO_x,CuSiO_x,CuZnAlO_x,CuMnAlO_x and CuZnCrO_x.The activity of the catalysts in the direct dehydrogenation of 1-methoxy-2-propanol to methooxyacetone was investigated in the fixed bed reactor.The preferred catalyst was CuZnAlOx,the conversion of propylene glycol methyl ether was 48.6% and the selectivity of methoxyacetone was 99.1%.The influence of reaction temperature,N₂ flow rate and ball grinding time on the performance of the catalysts were investigated.The prepared CuZnAlO_x catalyst has promising activity,stability and industrial applications.

ZnFe₂O₄ materials were successfully synthesized by hydrothermal method,and a series of ABiCl_0.7I_0.3-ZnFe₂O₄ composites were prepared by in situ growth method.The photocatalytic performance of ABiCl_0.7I_0.3-ZnFe₂O₄ composites was evaluated by photodegradation of Cr(Ⅵ) under visible light irradiation.The results showed that ABiCl_0.7I_0.3-ZnFe₂O₄ had enhanced photocatalytic activity than ABiCl_0.7I_0.3(ABiClI) or ZnFe₂O₄ (ZFO).ABiClI-ZFO-1 had the best removal efficiency for Cr(Ⅵ),and the removal effiency reached 100% after 30 min under visible light irradiation.Studies on charge carrier behavior by electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) showed that the synergistic effect of solid solution and semiconductor composite jointly promotes the efficient separation and transfer of photogenerated electrons (e^-) and holes (h⁺),resulting in the high photocatalytic activity.

Due to the increase of traditional fossil energy consumption and the severe problem of environmental pollution,the application of ecological renewable energy has attracted more and more attention.Among renewable energy,H₂ is considered to be the most popular and promising energy carrier.In this paper,through the template method,SBR-15 as the template,chitosan as the carrier and RuCl₃ as the precursor,a novel highly dispersed carbon nitrogen ruthenium based nanocatalyst was successfully prep-ared by high temperature calcination and acid etching,and was used for catalytic hydrolysis of aminoborane to hydrogen.The results show that the catalytic activity of carbon nitrogen ruthenium based nanocatalyst is significantly higher than that of traditional ruthenium nanocrystalline catalyst,and the reusability of the catalyst has been effectively improved.

Using 2.5% NaOH modified Artemisia annua as the binder,modified Artemisia annua coal was created by dry cold pressing,and modified Artemisia annua coal type coke was created by pyrolyzing six groups of raw Shenmu pulverized coal materials with various particle sizes.Using scanning electron microscopy(SEM) and infrared spectroscopy(FTIR),performance strength of the coal-type coke was evaluated.The experimental findings demonstrated that as compared to the FTIR spectra of the type coal,the intensity and quantity of the infrared distinctive peaks of the type coke were greatly reduced.Dehydration,cleavage,and condensation processes predominated throughout the pyrolysis process,which destroyed tiny molecules and active functional groups in huge amounts.The hydrocarbon chain structure was also condensed to increase the type of coke’s aromaticity,which was measured at 4.34.The performance strength of pulverized coal decreases with decreasing coal particle size because there is less space between the coal particles when they are molded and when they are expanded after demolding.The distance between pulverized coal particles expands with increasing coal particle size,allowing for additional binder to be added and producing a particular amount of engagement force with the coal particles to guarantee the coal’s performance strength.Coke outperforms coal in terms of total performance strength.During the pyrolysis process,some functional groups that include oxygen are replaced by C—C.Together with the release of volatile compounds,the resultant pores are equally distributed and have a wider wall thickness,which in turn assures the performance strength of the kind of coke.The performance strength of the type coke increases with the increase of pulverized Shenmu coal particle size.When the particle size of Shenmu pulverized coal is (3-1.5) mm,the compressive strength of the type coke is 3 338.9 N/pc,the drop strength is 98.96%,and the crushing strength is 83.16%.

1-butyl-3-methylimidazole chloride was selected as an ionic liquid promoter to prepare ruthenium based catalysts,and small-scale,mode,and industrial side line catalytic performance was evaluated for acetylene hydrochlorination reaction.Combining multiple characterization methods such as BET,ICP,TG and UV-Vis,the reasons for the deactivation of ruthenium catalysts were analyzed.The results show that the addition of ionic liquids can significantly reduce the apparent activation energy of the catalyst and improve its activity,and the best catalytic performance was obtained for the catalyst with ionic liquid loading of 5%(mass fraction) which exhibited excellent activity and stability in small-scale experiments and modes.During industrial side line operation,the catalyst has excellent initial activity,but as the reaction temperature increases,the catalyst deactivation accelerates.There are three main reasons for catalyst deactivation including the loss of active components carried by the catalyst promoter,the carbon deposit on the catalyst surface,and the reduction of active components of the catalyst.The loss of additives and active components dominates.

Hydrodesulfurization is an important technology for organic sulfur removal.Presulfurization is the process of converting the hydrogenation catalyst from the oxidation state to the active sulfurized state,which is a key treatment process for the hydrogenation catalyst.Elemental sulfur as a presulfiding agent is attracting extensive attention of researchers in recent years due to its advantages of non-toxicity and high sulfurization efficiency.This review summarizes the progress of research on elemental sulfur presulfurization catalysts,in order to provide reference for the development and application of hydrogenation catalyst presulfurization process.Firstly,the presulfurization mechanism of elemental sulfur sulfide hydrogenation catalysts was introduced,and the influencing factors of the presulfurization process were analyzed,including the amount of elemental sulfur introduced, presulfurization temperature,pressure,and time.Secondly,elemental sulfur as a presulfiding agent has advantages compared with other presulfiding agents,but there is a problem of easy sublimation during the presulfurization process.In response to this issue,a detailed introduction was provided on the impact of different introduction methods on the retention of elemental sulfur in catalysts.Subsequently,an overview was provided of the industrial applications of sulfur presulfurization hydrogenation catalysts both domestically and internationally.Finally,a summary was made and the future research direction of elemental sulfur presulfidation hydrogenation catalysts was prospected.It was proposed to further improve the sulfidation by studying the interaction and mechanism of elemental sulfur and metal oxides with the goal of obtaining active sulfides.This is the key to improving the presulfurization effect of elemental sulfur and subsequent catalytic hydrogenation activity performance.

Succinic acid is an important biodegradable plastic monomer that can be synthesized through multiple routes.This article introduced the current market situations and various production routes of succinic acid,including biological fermentation,furfural oxidation,(double) carbonylation,and maleic anhydride hydrogenation,and their advantages and disadvantages were briefly analyzed.The effect factors for products distribution in the maleic anhydride hydrogenation process was emphasized under different systems such as gas phase,organic phase,and aqueous solution,as well as the latest research progress on related catalysts,including precious metal catalysts,non precious metal catalysts and so on.Finally,the future research and development direction of succinic acid were prospected,developing non-noble metal catalysts with superior performance,good stability,and low cost in aqueous-phase systems is the technological trend for the development of succinic acid (anhydride) industry in the future.

Plastics have brought convenience to people’s lives but have also caused serious pollution,and the depletion of fossil energy has forced us to embark on the road of sustainable development.The high-value recycling of waste plastics is an effective way to solve the current energy shortage and environmental pollution.Plastic waste recycling methods include chemical method,energy recovery,recycling method and so on.Microwave-assisted pyrolysis in chemical recovery utilizes special interactions between electric fields and polymer molecules,which has potential advantages in plastic pyrolysis applications.This paper reviews the research status of microwave assisted pyrolysis (MAP) of plastics to obtain liquid oil,gas and other high value-added products.According to different kinds of waste plastics,microwave processing parameters,characteristics of microwave absorbent and the action of catalyst were analyzed,and the influencing factors on the distribution and quality of pyrolysis products were discussed in combination with the process method of microwave pyrolysis plastics to produce oil.

In recent years,oxidative desulfurization (ODS) technology has garnered significant attention due to its efficient and thorough removal of sulfides from oil products.By utilizing the appropriate catalyst at specific temperature and pressure conditions,the oxidizer’s activity can be greatly enhanced,thereby achieving rapid sulfide elimination.Among various oxidation desulfurization systems,the hydrogen peroxide (H₂O₂) system is favored for its environmental friendliness and high efficacy.This paper provides a comprehensive review on the latest advancements in ODS technology employing H₂O₂ as an oxidant and metal or non-metal materials as catalysts in the field of oxidative desulfurization.Future development directions of this field are also proposed.

Alkyl anthraquinone is mainly used in the hydrogen peroxide production industry,and in recent years,with the development of related industries,its industrial demand has become increasingly large.At present,the main method for synthesizing alkyl anthraquinone in China is the phthalic anhydride method,which generates a large amount of waste acid and aluminum containing wastewater during the production process resulting in enormous environmental pressure.Solid acids can replace traditional aluminum trichloride and concentrated sulfuric acid in the reaction and greatly reduce the emission of pollutants.The research progress on solid acids in the catalytic synthesis of alkyl anthraquinone is reviewed.The applications of solid acids in the catalytic acylation,dehydration closed-loop and one-step reactions are introduced.The advantages and disadvantages of solid acids in the use process at present and future research directions are also pointed out.

Cobalt-based catalysts are prone to aggregation and sintering at high temperatures,leading to insufficient understanding of their active centers.To address this issue,a novel CoLa bimetallic catalyst was designed in this study.By using the rare earth metal La to isolate and stabilize cobalt species,the catalytic activity was enhanced.By controlling the doping amount of La in the material,a correlation between different dispersion degrees and catalytic performance was established to gain insights into the active centers.Various characterization techniques including XRD,XPS,chemical adsorption,and probe molecule infrared spectroscopy were employed to analyze the form,chemical environment,and size of cobalt species in the catalyst.The results indicate that La promotes the dispersion of cobalt species and enhances the interaction between cobalt species and the support.

Photothermal coordination has shown great potential in catalytic reduction of CO₂ because of the high thermodynamic stability of the CO₂ molecules and the low efficiency of the photocatalysts in visible light absorption and utilization.Here,the preparation of bismuth (Bi) photocatalyst is achieved by directly reducing of Bi³⁺ in aqueous solution by NaBH₄.The photocatalytic CO₂ reduction to CO with the help of H₂O over the elemental Bi was investigated under visible-light irradiation at 200 ℃,which is termed as photocatalytic-thermal CO₂ reduction.It was confirmed that the simple Bi has the photocatalytic ability in the whole ultraviolet and visible light region.Under irradiation at 450 nm,generation rate of CO was 5.4 μmol·(g·h)^-1.The synergetic effect between light irradiation and heating contributes to the excellent catalytic activity of Bi.The above results demonstrated there was no significant decrease in CO yield after 4 cycles.

Sodium m-aminobenzene sulfonate is an important intermediate in chemical industry.There are many methods for its preparation,and catalytic hydrogenation is the main method used at present.But its industrialization report is few.It is because of the deactivation of the catalyst in hydrogenation process,and it’s difficult for catalyst recycle leading to high industrialization cost.In this article,we use self-made Pd/C catalyst in hydrogenation reaction.The deactivation reasons of catalyst were explored by LC-QTOF-MS,XRD,XPS,and BET.The deactivation of Pd/C catalyst is because the sodium m-aminobenzene sulfonate was converted to azoic compound and azoxy compound,which could block the pore of carbon support due to strong adsorptivity.The reduce of catalyst specific surface area due to the above reason can result in temporary toxic deactivation of catalyst.The deactivation is not permanent caused by formation of palladium sulfide.

Hexagonal wurtzite ZnO crystals with different morphologies were prepared by hydrothermal method in different conditions of Zn precursor,surfactant and hydrothermal temperature.Au nanoparticles as cocatalysts were successfully loaded on the synthesized ZnO and the catalysts were characterized by FESEM,XRD and ICP.The activity and selectivity in photocatalytic OCM were investigated.The results show that the about 30 nm pointed-shaped ZnO nanoparticles significantly enhanced photocatalytic methane conversion activity.The photocatalytic activity of flower-like ZnO nanosheets is slightly lower than commercial irregular ZnO nanoparticles,but the C₂₊ reaction selectivity is higher.The hexagonal prism ZnO nanorods show extremely low photocatalytic reactivity,but still show a similar selectivity.The pro-catalyst with appropriate morphology and crystal facet is crucial for improving the photocatalyst performance.

The low-coke activity slow-release heavy oil cracking catalyst M was developed by alkaline earth metal composite modification and solid rare earth technology,and was used in the heavy oil catalytic cracking unit of R Petrochemical Company.The application results show that the catalyst has high conversion capacity of heavy oil and low coke production.Compared with blank calibration,when the new catalyst M accounted for 50% of the system reserve,the liquid yield increased by 1.64 percentage points,the oil slurry yield and coke yield decreased by 0.44 and 1.30 percentage points,the gasoline yield increased by 0.62 percentage points,and the diesel oil yield increased by 1.58 percentage points.

A large-scale synthesis of an aromatic polyamine compound,2,4,6-triaminotoluene (TAT),was achieved through catalytic hydrogenation using 2,4,6-trinitrotoluene (TNT) as raw material and commercial palladium carbon (Pd/C) as catalyst.The successful synthesis of TAT was demonstrated through infrared spectroscopy,nuclear magnetic resonance spectroscopy,and high-resolution mass spectrometry testing.When the dosage of TNT is 1 kg and the dosage of ethyl acetate is 10 L,the optimal process parameters for TAT synthesis reaction are 5%Pd/C dosage of 40 g (dry material),reaction temperature of 60 ℃,hydrogen pressure of 1 MPa,and stirring rate of 650 r·min^-1.The safety study of TNT hydrogenation reaction shows that TNT hydrogenation reaction is exothermic,with an average exothermic rate of 38.2 W·kg^-1 and an adiabatic temperature rise of 150.85 ℃.There is no possibility of secondary decomposition reaction caused by uncontrolled reaction.

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.

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.

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.

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.

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.

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

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.

In this paper,nanorods MnO₂ modified g-C₃N₄ composite heterojunction photocatalysts were prepared by hydrothermal method.The characterization of XRD,FT-IR and PL proved that the molecular structure and chemical bonds of the composite materials were not destroyed,and the recombination of the hole-electron pair was effectively inhibited.Under the system of photocatalysis-Fenton-like reaction,the degradation performance and mechanism of MnO₂/g-C₃N₄ composite photocatalysts in RhB solution were investigated.In the experiment,the degradation of 50 mL RhB(20 mg·L^-1) solution using 25 mg 11%-MnO₂/g-C₃N₄ catalyst reached 95% in 10 minutes,and the maximum degradation reached 99% in 60 minutes.It was found that the superoxide anion radical (·O₂^-) contributed mostly to the degradation of RhB in the photocatalytic-Fenton-like system of MnO₂/g-C₃N₄.

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.

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.

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.

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.

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.

Hydroformylation of olefin is an important homogeneous catalytic reaction in industrial production,and its industrial application is limited by the difficulty of catalyst separation and recovery.Heterogeneous catalyst can make up for the deficiency of homogeneous catalyst,but the activity is rela-tively low and the regional selectivity is poor.Therefore,the development of highly efficient heterogeneous catalysts has important practical value for the development of hydroformylation industry.Single atom catalysts(SACs) have the advantages of high atom utilization,stable active site,easy separation and recovery,and are expected to be widely used in the field of hydroformylation as a bridge between homogeneous and heterogeneous catalysts.The research progress of different SACs in this field was reviewed,with emphasis on the influence of microstructure on the activity,stability and regional selectivity of the hydroformylation of olefin catalyzed by SACs.Finally,the challenges facing the industrial application of SACs were summarized.

It is an effective environmental protection measure to remove CO from steel sintering flue gas by catalysis technology.The supported Pt/TiO₂ catalyst is prepared with Pt as the active component,and the reaction mechanism of H₂O and SO₂ on the catalyst surface is investigated.XRD,Raman and In situ DRIFTS are used to reveal the chemical changes on the catalyst surface under different flue gas conditions.The results show that the low concentration of H₂O can decompose the hydroxyl group at high temp-erature,thus promoting the CO catalytic activity of Pt/TiO₂.At low temperature,there is competitive adsorption between SO₂ and reaction gas on the surface of Pt,which makes it difficult to activate the catalyst.At high temperature,SO₂ reacts with oxygen species on the surface of Pt to form sulfate,which destroys the chemical composition of the catalyst surface.When SO₂ and H₂O were introduced at the same time,the toxicity of SO₂ was further enhanced.

Methane is an important greenhouse gas,and controlling its emission can not only reduce the warming effect but also reduce environmental pollution.The PtPd/ZrO₂ catalyst was prepared by impregnation method and its catalytic performance for methane combustion under the condition of water and sulfur was investigated.XRD,H₂-TPR,HAADF-TEM and XPS were used to analyze the structure,reduction performance and surface chemical state of the catalyst.The reasons for the improvement of sulfur resistance were investigated In situ DRIFTS.The results show that,compared with the dry condition,the total methane conversion temperature of PtPd/ZrO₂ only shifts to the high temperature by 62 ℃ under the condition containing H₂O and SO₂.The interaction between the bimetals promotes the dispersion of the support surface,affects the chemical state of the precious metal and improves the REDOX performance of the catalyst.The bimetal did not affect the adsorption of methane but inhibited the sulfation of active metal and reduced the total sulfate deposition on the catalyst surface.

As the third largest greenhouse gas,N₂O can not only cause strong greenhouse effect,but also seriously destroy the ozone layer.Three-dimensional Co₃O₄(x-y) catalysts were prepared by hydrothermal synthesis with a mixture of ethylene glycol and water as solvent,and were used to directly catalyze the decomposition of N₂O.By adjusting the amount of ethylene glycol and water,Co₃O₄ catalysts with different three-dimensional morphology such as flower,lamellar and sea urchin were obtained.The results show that Co₃O₄(10-50) catalyst has the best catalytic performance of N₂O decomposition.Under the conditions of 400 ℃,N₂O/Ar volume ratio of 0.2% and gas flow rate of 50 mL·min^-1,the N₂O conversion rate can reach 95.4%,and has good stability.

Ga-ZSM-5 with different ratio of gallium to aluminum and Ga-S-1 with different content of gallium were prepared by means of seed induction and hydrothermal synthesis of Ga-S-1 nanoparticle molecular sieves with thickness less than 100 nm using gallium nitrate hydrate as precursor.The samples were characterized by XRD,SEM and NH₃-TPD,and the catalytic cracking performance of methanol coupled butene was investigated in a gas-phase continuous micro-fixed bed reactor.The results showed that comp-ared with ZSM-5,the acid strength and acid content of GA-ZSM-5 were decreased,and the introduction of Ga prevented Al from entering the molecular sieve framework.Using Ga-ZSM-5 as catalyst,the selectivity of ethylene and propylene in the product can be increased by (4~5) percentage points.At the same time,the selectivity of low carbon alkane in the product is reduced.Using GA-S-1 as catalyst,with the increase of n(Si)∶n(Ga) to 100,the ratio of n(propylene)∶n(ethylene) in the product is about 7,which is nearly 2 times higher than that of ZSM-5.At the same time,the yield of byproduct C₂~C₄ alkanes decreased by (30-50) percentage points.