The coating technology and the combination mechanism of coating and carrier were summarized.Three commonly used catalyst coating technologies,including roller coating,spray coating and dip coating,were introduced and compared.The requirements of the three coating technologies on the properties of raw materials and coating process were summarized.Roller coating material is powder,the product is mainly spherical coating catalyst.Spraying and dipping coating material is slurry,the product can be coating catalyst of various shapes.The research progress of roller coating,spray coating and dip coating catalysts were summarized respectively.The effects of coating process parameters optimization,raw material property modification and selection of additives on the performance of coating catalyst,as well as the methods to improve the physical and chemical properties of coating catalyst were discussed.The main reason for limited application of coated catalysts is that it is difficult to consider both mechanical properties and reaction properties.Effectively improving the comprehensive performance of coated catalyst and its application value are focus of future coating technology research.

Alkoxycarbonylation of alkenes is one of the most important homogeneous reactions for the industrial production of esters.And the development or the modification of its catalyst has been paid extensive attention.Furthermore,the recovery of homogeneous catalysts and “CO-free” carbonylation have been the research focus of alkoxycarbonylation.In this paper,the research progress on alkoxycarbonylation catalysts in recent years was reviewed,and the effects of the different active groups in bisphosphine ligands on the alkoxycarbonylation activity of the catalyst were summarized.Moreover,the immobilized homogeneous alkoxycarbonylation catalysts and the liquid-liquid biphasic systems were introduced for the catalyst recovery,and the efficient carbonylation of alkenes with three carbonyl substituents of formic acid,formaldehyde and CO₂ was discussed,respectively.

This paper summarize the photocatalytic degradation of methyl orange (MO) processes,including catalysts,reactors,influence factors,and measures to improve the efficiency of photocatalytic reactions.The efficiency of MO degradation by different catalyst systems is highlighted in the review,and advances in photocatalytic reactors are also presented.The electron-hole separation-transfer efficiency of the catalyst surface and the alignment of the reactor light source with the solution transmission rate are crucial for enhancing the photocatalytic degradation of MO.Therefore,the authors divided the currently available methods for enhancing MO photocatalytic degradation into three categories:(1)Enhancing the light absorption capacity of the composite catalyst;(2)Homogenizing the light source in the reactor;(3)Increasing the loading mechanism of the catalyst to increase the contact-specific surface area and micro-flow characteristics.The idea of increasing the efficiency of photocatalytic is presented in this paper.It is necessary to start with the discrepancy between the source distribution and the transmittance of the solution,and then optimize the source arrangement in the reactor based on the uniform light distribution.

The oxidation of benzene to phenol with H₂O₂ as oxidant has become an important way for production of phenol which is an important industrial raw material.The research progress on iron based-,copper based-,vanadium based- and other single metal/multi metals based-,and nonmetal based- heterogeneous catalysts in H₂O₂ system for benzene hydroxylation to phenol was reviewed.The catalytic performance and reaction mechanism were emphatically discussed,aiming to provide a fresh perspective for the design of catalysts and the preparation of phenol in heterogeneous system.

Supported metal nanoparticles are widely used as catalysts in the chemical industrial,but still suffer from deactivation because of metals sintering at high temperature.Therefore,improving the high temperature thermal stability of catalysts is a major challenge in the field of heterogeneous catalysis.This paper briefly reviews the sinter mechanisms of metal nanoparticles,such as particle migration and coalescence (PMC) and Ostwald ripening (OR).Furthermore,the recent research progress on preparing sinter-resistant metal-nanoparticle catalysts via strengthening metal-support interactions,adjusting the interface effect between metal nanoparticles and coatings,and constructing multi-functional structures are discussed and summarized.

Aromatic nitrifying products play an important role in the synthesis of intermediates such as medicine,rubber,explosives,dyes and pesticides due to their high added value and structural diversity.At present,the traditional aromatic nitrification is mixed acid nitrification.The process is mature,but often accompanied by poor selectivity,difficult waste acid treatment,serious environmental pollution and other problems.In recent years,with the continuous in-depth research on green nitrification catalysts,the development of green catalytic system to replace the traditional mixed acid nitrification has become a research focus in this field.In this paper,the research progress of solid acid,ionic liquid,transition metal and other green catalysts in the nitrification of aromatic hydrocarbons is reviewed.The limitations of this research field and the prospects of green and clean development in the future are summarized and prospected.

Ethanol is an important low-carbon platform molecule,and its downstream conversion to produce high value-added chemicals has attracted much attention.The conversion of ethanol via dehydrogenation to ethyl acetate is a competitive reaction route.In this paper,a series of CuCeZr catalysts were synthesized by coprecipitation method.In particular,the influence of pH value of coprecipitation on the catalytic performance of catalyst was investigated.Furthermore,the influence of reaction conditions,including reaction temperature,pressure and space velocity were investigated and optimized.The results show that the precipitation pH as 12 was benefit for the selective generation of ethyl acetate from ethanol.And the ethanol conversion and ethyl acetate selectivity achieved 45.6% and 80.6%,respectively at 240 ℃,1.0 MPa using ethanol aqueous solution as raw material (0.1 mL·min^-1) and free of carrying gas.The results of 250 h continuous reaction indicated the good stability of CuCeZr catalyst.

Triplet photosensitizers are widely used in photocatalysis.The conventional photosensitizers based on precious metal complexes were limited in further applications due to the weak absorption of visible light,short triplet excited state lifetimes and the high cost.Therefore,it is important to develop novel triplet photosensitizers with strong absorption of visible light and long triplet excited state lifetime.This review briefly introduces the photochemical basic theories and catalysis process of photocatalysis involving triplet photosensitizers.We also introduce the recent progress on BODIPY as triplet photosensitizer in photocatalytic synthetic organic reactions and photocatalytic hydrogen evolution.Finally,we further clarify the development expectation of triplet photosensitizers on photocatalysis.

The rare earth catalytic materials play an important role in petrochemical industry,fossil fuel catalytic combustion and other fields.As an important rare earth metal oxide,cerium dioxide (CeO₂) is widely used in catalytic reactions due to its excellent oxygen storage capacity and stable surface-centered cubic structure.This paper focuses on the application of CeO₂ in CO₂ catalytic transformation and the recent research progress,including the CH₄-CO₂ reforming reaction,the direct reaction of CO₂ and methanol to synthesize dimethyl carbonate,and the CO₂ catalytic hydrogenation to methanol reaction.The influence of morphology control on CeO₂ crystal surface exposure,oxygen vacancy and the process of CO₂ adsorption and dissociation on the catalyst surface were described.Finally,the development direction of CeO₂ based catalyst was prospected.

The synthesis of methyl acrylate by condensation of methyl acetate and formaldehyde has attracted extensive attention in academia and industry.Herein,the Cs solid base catalysts supported by silicon dioxide were prepared by incipient-wetness impregnation method and employed.Combining the evaluation of catalyst performance with a series of catalyst characterization (SEM,Raman,XRD,TG-MS and CO₂-TPD),the effects of different Cs precursors on the structure and reaction performance of the catalysts were investigated.It was found that the catalyst prepared by cesium carbonate or cesium acetate precursor had superior performance,while that prepared by cesium nitrate precursor had lower performance,which may be due to poor dispersion of active phase caused by melting and recrystallization of cesium nitrate at 406 ℃.The active sites of the catalyst prepared by cesium carbonate or cesium acetate precursor exist in the form of Cs₂CO₃ phase after high temperature calcination.The effect of cesium carbonate loading on the performance of the catalyst was further investigated.Under the optimal loading of mass fraction of 5%,conversion of methyl acetate is about 20% and selectivity of methyl acrylate is about 87%.The catalyst had been stable for 120 h,indicating excellent stability.

As a copper-based small-pore zeolite denitration catalyst emerging in recent years,Cu-SAPO-34 has the characteristics of large specific surface area,rich acid sites and stable framework.It has attracted much attention due to its excellent catalytic activity and hydrothermal stability.The preparation methods of Cu-SAPO-34 catalysts at home and abroad were introduced,such as wet ion-exchange,one-step hydrothermal synthesis,solid state ion-exchange,impregnation and deposition-precipitation.The effects of modification methods such as rare earth element doping,transition metal doping and mesoporous introduction on the denitration performance of Cu-SAPO-34 catalysts were reviewed.And the future development direction of Cu-SAPO-34 denitration catalyst was also prospected.

Propylene oxide (PO) is an important organic chemical raw material,which is mainly used to produce polyether polyols,propylene glycol, various non-ionic surfactants,and so on.The research prog-ress on catalytic selective epoxidation of propylene to propylene oxide in recent years were reviewed in this paper,including the catalytic processes with oxygen,H₂O₂,in situ generation of H₂O₂ and organic peroxides as oxidant.Green catalytic process for preparing propylene oxide in the future were expected.It is necessary to focus on the propylene epoxidation process of biomimetic catalysis,in situ H₂O₂,design of high selectivity catalyst and the catalytic reaction mechanism.

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.

Based on the process conditions analysis of nitrobenzene hydrogenation to aniline in fluidized bed,the effects of various process conditions on the reaction were discussed,such as catalyst fluidized state,quality of nitrobenzene and hydrogen,hydrogen oil ratio,nitrobenzene feed temperature,reaction temperature,reaction pressure and catalyst.According to the actual opearting conditions and data in industrial production,the influence of some process conditions on the reaction was excluded.And the source of light components in aniline products produced by fluidized bed process was analyzed.This study will have a guiding significance for industrial production and operation.

The accumulation of waste plastics in nature is causing serious environmental pollution.To solve the environmental pollution and utilize waste plastics as one kind of carbon resource,it is urgent to distribute waste plastics to recycling routes.Chemical recycling can depolymerize waste plastics into high value-added chemicals with high selectivity.This paper summarizes the recent research progress of chemical recycling,including direct pyrolysis,catalytic pyrolysis,hydrocracking and other recycling methods,and focuses on the influence of catalysts and catalytic systems on product distribution and the corresponding reaction mechanism.Catalytic strategies should play an important role in promote the industrial application of waste plastic chemical recycling technology.

As one of the most widely used catalysts in industry,the ZSM-5 zeolite has been a hot spot for research.However,the conventional ZSM-5 zeolite suffer from large grains,diffusion difficulties and poor accessibility of active sites,which limit the application in macromolecular catalysis.The methods and mechanisms to improve the diffusion difficulties of zeolite by adjusting the gel chemistry and synthesis condition factors in recent years are reviewed,and it is pointed out that the use of long-chain quaternary ammonium salts as structural guides can synthesize ZSM-5 zeolite with self-pillared structure and good intercrystalline mesopore connectivity,but their preparation process is tedious and expensive.The introduction of additives such as urea and seeds and the successful application of two-stage crystallization method make the synthesis less costly,and the improved intergranular mesopores will make it have better diffusivity.

Solvent-free synthesis of molecular sieves has many advantages,such as low raw material cost,mild reaction conditions,simple synthesis route and green process,and has gradually become a research hotspot in recent years.This paper mainly studies the progress of molecular sieve synthesis by solvent-free method,the synthesis mechanism of molecular sieve,and the advantages and disadvantages of synthesis by solvent-free method.The application prospect and research trend of this synthesis are also prospected.

As an important organic chemical raw material,ethylbenzene is mainly used to produce styrene,and then to produce engineering plastics and synthetic rubber.In the early stage,the AlCl₃ process,with strong corrosiveness and serious discharge of wastes,was absolutely dominant in the industrial production of ethylbenzene.Since developed by Mobil company and Badger company in the 1970s,ethylbenzene production technologies based on zeolite-catalyzed alkylation,without corrosion and pollution,have made great progress and become the mainstream technology for ethylbenzene production today.In general,zeolite-catalyzed alkylation can be divided into vapor-phase alkylation and liquid-phase alkylation.Pure ethylene,bioethanol and dilute ethylene can all be used as raw material for vapor-phase zeolite-catalyzed alkylation,which shows the characteristics of strong anti-poisoning ability for catalyst,simplicity for process and flexibility for equipment.While liquid-phase zeolite-catalyzed alkylation can be divided into EBOne process,EBMax process and CD-TECH process,possessing the features of low reaction temperature and low impurity content.This paper focuses on the outstanding progress made in the independent innovation of ethylbenzene production technology in China,and looks forward to the production technology of ethylbenzene in China from four aspects including diversification of raw materials,enlargement of equipment,low carbonization of process,and cleaning production of zeolite catalyst.

Aldol condensation of furfural with cyclopentanone is one of the important steps in preparation of the high-quality biofuels.The synthesis of renewable biofuels from biomass furfural and cyclopentanone is sustainable and meets the requirements of green chemistry.However,the catalytic mechanism of this reaction are not very clear.Under different catalysis,two products can be obtained,2,5-bis (2-furanylmethylene) cyclopentanone (F₂Cp) and 2-(2-furanylmethylene) cyclopentanone (FCP).In this paper,the catalytic performances of acid catalyst,base catalyst and acid-base bifunctional catalyst used in the reaction for target product of F₂Cp were analyzed.The analysis shows that both acidic Al₂O₃ catalyst and acid-base bifunctional Na-HAP catalyst have better catalytic performance.The microwave radiation method can increase the reaction rate under free solvent.On this basis,the catalytic mechanism is described and analyzed.The mechanism analysis shows that the acid-base synergism is beneficial to the aldol condensation reaction.Therefore,the design and preparation of solid acid-base bifunctional catalysts with appropriate acid-base ratio is the focus of the follow-up study of this reaction,and also provide some references for the aldol condensation reaction of other aldehydes or ketones.

Hierarchical porosities molecular sieves have attracted much attention because of their developed pore structure,excellent hydrothermal stability,higher pore volume and specific surface area,which can effectively alleviate the problem of macromolecular diffusion limitation of traditional single pore zeolites and greatly improve the structural properties of molecular sieves.In this paper,the research progress on the preparation of hierarchical pore molecular sieves at home and abroad in recent years was reviewed,especially on the preparation process of hierarchical porosities of molecular sieves.The post-treatment method including dealumination method,desilication method and dealumination-desilication combined method,and the in-situ synthesis method including hard template method and soft template method were focused on.The advantages and problems of each preparation method were discussed from the aspects of stability and operability.Based on the difference of pore size,the research status on three kinds of hierarchical zeolites,namely micromesoporous,micromacroporous and micro mesoporous-macroporous zeolites,were briefly summarized in the aspects of preparation process and catalyst application,and the future development direction of hierarchical porosities molecular sieves was prospected.

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.

Methylcyclohexane (MCH) is considered to be the most promising organic liquid hydrogen storage material with high theoretical hydrogen storage capacity and superior physical and chemical properties.The Methylcyclohexane-Toluene-Hydrogen (MTH) cycle realizes the cycle utilization of materials and energy, which has good industrial application prospects.However, the MTH cycle can not be used on a large scale because of the catalyst used in the dehydrogenation of MCH has poor activity at low temperature and instability at high temperature.In order to solve this problem, previous researchers have carried out extensive research and found that the design of catalyst is the core of solving this problem.In view of this, the current situation of MCH dehydrogenation catalysts were reviewed, the research progress, advantages and disadvantages of mono-, bi-and tri-metal catalysts were introduced with emphasis, the influence of the synergistic effect of active component, support and promoter on the catalysts were analyzed, and the future research directions of catalysts was prospected.Based on the existing analysis, it is believed that adding a second metal element, adjusting the properties of the catalyst support and using Ni metal as the active component can obtain high stability, high activity and low cost MCH dehydrogenation catalyst in the future studies to meet requirements of commercial applications.

In this paper,the research progress on supported VO_x,ZnO_x and GaO_x catalysts for propane dehydrogenation in recent years is reviewed.Under the reaction conditions of high temperature (500-650) ℃ and reducing atmosphere (propane and its derivatives),the active sites of supported VO_x,ZnO_x and GaO_x metal oxides are usually partially reduced,and the generated metal cations with unsaturated coordination are typically the active sites of dehydrogenation reaction.The effects of the dispersion of active sites various oxides,carriers,preparation methods,acidity and alkalinity on the C-H activation of propane,propylene selectivity and catalyst stability were systematically summarized,which laid a certain foundation for the further design of efficient supported oxide catalysts for propane dehydrogenation.

TiO₂ carrier has good catalytic performance,stable physical and chemical properties and non-toxic characteristics.The advantages of titanium dioxide as denitration catalyst carrier are introduced on the basis of catalyst carrier loading active components.The forming of titanium dioxide carrier and application of titanium dioxide carrier in denitration industry were reviewed.Pure titanium dioxide and titanium dioxide carrier loaded with vanadium,tungsten,rare earth cerium,etc. as denitration catalysts are two main applications of TiO₂.The future development direction will focus on improving the service life of titanium dioxide carrier,preventing titanium dioxide carrier poisoning and adding more active components,and improving the service life of denitration catalyst and denitration efficiency to meet the increasingly stringent environmental requirements of ultra-low emissions of flue gas and mobile source tail gas.

As the key of cyclohexanone production using benzene as raw material,selective hydrogenation catalyst has been monopolized by foreign countries for a long time.The development of cyclohexanone and its downstream products,including caprolactam,nylon 6,nylon 66 and various fiber products in China was limited.Through joint technical breakthrough,Inner Mongolia Ruixiangtuo Innovative Materials Co.,Ltd.successfully developed a selective hydrogenation catalyst for benzene and applied in 200 kt·a^-1 caprolactam production unit of Inner Mongolia Qinghua Group Co.,Ltd..The results showed that conversion of raw benzene reached 40%-50%,and the selectivity of cyclohexene reached more than 80%,which were better than foreign imported products.The catalyst provides important technical guarantee for the stable operation of domestic benzene selective hydrogenation to cyclohexanone units and process optimization. Moreover,price of the catalyst is moderate,which is of great significance for the cost reduction and efficiency increase of domestic units and reduction of dependence on foreign hydrogenation catalysts.

During the use of imported MT titanium catalysts in Innovene S HDPE plant,the plant suffered from rapid increase of reactor axial pump power,short production cycle and inability to increase production load.By trialing domestic and foreign titanium catalysts in HDPE bimodal products,activity and their effects on reactor operating conditions and products were compared.The results of industrial tests show that the activity of BCL and SEL domestic catalysts is nearly 60%-80% higher than that of imported catalysts.The particle size distribution of polymer powder is narrow,and the fluidity is better.The mechanical properties of the produced resin are comparable to those of imported catalysts, which is conducive to the stable production of higher load of the device.The application of domestic catalysts can extend the life cycle of bag filter,stablize the power of axial flow pump,improve he economic efficiency,and solve the current problems of imported MT titanium catalyst.

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.

As the crude oil reserves decreased dramatically,it’s urgent to upgrade heavy feedstocks into light oils to relieve the supply pressure of crude oil.The slurry-phase hydrogenation is an advanced technology to efficiently upgrade heavy feedstocks.The challenge of slurry-phase hydrogenation lies in developing high active hydrogenation catalysts.In this work,MoS₂/C catalysts were synthesized by a facile one-step hydrothermal method with glucose and maltose as the soluble carbon sources.The compositions and structures of MoS₂/C catalysts were characterized by X-ray diffraction,Raman spectroscopy,elemental analysis,scanning electron microscopy and high-resolution transmission electron microscopy.The characterization results indicated that the MoS₂/C catalysts are composed of nanosheets with MoS₂-C-MoS₂ carbon intercalated structure.The nanosheets display enlarged interlayer distance,short slabs and few stacking layers.The catalytic hydrogenation activities of MoS₂/C catalysts were evaluated with phenanthrene as the model compound of heavy oils in the slurry-bed reactor.MoS₂/C catalyst with glucose as carbon precursor and the C to Mo atomic ratio of 5 in the raw materials exhibits the highest catalytic hydrogenation activity.For MoS₂/C-G-5 catalyst,the phenanthrene conversion,hydrogenation percent of phenanthrene and the selectivity to the deep hydrogenation product octahydrophenanthrene can respectively reach 85.6%,37.4% and 56.4%,which are 1.6,2.4 and 2.3 times as high as those of MoS₂ catalyst synthesized without carbon source.The MoS₂-C-MoS₂ carbon intercalated nanostructures of MoS₂/C catalyst could expose more hydrogenation active sites to improve its hydrogenation activity significantly.

The principle of adsorption and removal of benzene series by zeolite molecular sieves was described,and the methods,which including zeolite molecular sieve structure optimization,weakening hydrophilicity,cation compensation,pore multi-polarization,composite molecular sieve and so on, to improve the adsorption and removal performance of zeolite molecular sieves were discussed.When the flow rate is large and the pressure drop is high,the molecular sieve runner adsorption technology has high adsorption and removal efficiency for benzene series,and this technology is widely used in the industrial field.In addition,the problems to be solved in the adsorption and removal of benzene series by zeolite molecular sieves are improving hydrophobicity,stability and selectivity.

The hydrogenation of coal tar to produce clean oil is an effective method to realize efficient conversion of coal tar.With the continuous improvement of fuel oil standard in our country,denitrification and desulfurization of coal tar has become a research hotspot.In this paper,the properties of coal tar and the hydrogenation process of coal tar are introduced,the research status of catalysts for hydrogenation of coal tar is reviewed,and the research direction of catalysts for hydrogenation of coal tar is prospected.It is pointed out that the development of new green-friendly hydrogenation catalyst is the key to realize the coal tar hydrogenation technology.

Pd/AC catalyst prepared by impregnation method for the hydrogenation of farnesylacetone has deactivation phenomenon during the reaction process.After regeneration treatment,the catalyst activity was effectively recovered.The physical and chemical properties of the catalysts were analyzed by means of XRD,N₂ adsorption-desorption,ICP-AES,TEM,TG-MS,etc.,and the deactivation mechanism was explored.The results show that the particle size of the active metal Pd increases during the reaction process,and there is obvious carbon deposition.The metal agglomeration has little effect on the catalyst activity.The deactivation of the catalyst is mainly caused by carbon deposition,which is reversible deactivation.

A serious of V-Mo/Ti De-NO_x catalysts with different amount of MoO₃ were prepared on the industrial production line.XRF,XRD,N₂-adsorption,abrasion strength,Raman,H₂-TPR,NH₃-TPD,SO₂-TPD,and TG were used to characterize the physicochemical properties of the different catalysts.The catalytic activities of catalysts were tested in a fixed-bed micro-reactor.Besides,the effect of MoO₃ on the SO₂ oxidation activity of different catalysts was investigated by stability tests.The results showed that the amount of MoO₃ had little impact on the crystal structure and pore structure of V-Mo/Ti catalyst,but could lead to the decrease of mechanical property of V-Mo/Ti catalyst.V-Mo(5)/Ti catalyst exhibited similar acidity and better reducibility than that of V-Mo(3)/Ti catalyst.As a result,V-Mo(5)/Ti catalyst possessed higher catalytic activity.When mass fraction of MoO₃ reached to 6.98%,catalyst acidity decreased obviously,leading to the decline of catalytic performance.The increase of MoO₃ could increase the N₂O generation during the SCR reaction process,and decrease the SO₂ adsorption ability of the catalyst,which was benefit to decrease the generation of ammonium bisulfate.Overall,V-Mo(5)/Ti catalyst revealed the best catalytic performance among the investigated catalysts.

When concentration of nitrogen oxides (NOx) in the atmosphere exceeds the self-purification capacity of the environment,it will lead to acid rain,photochemical smog,destruction of the ozone layer and eutrophication.In addition,nitrogen oxides in the atmosphere will participate in the formation of air pollutant PM_2.5 and O₃,seriously endanger human health and damage terrestrial and aquatic ecosystems.Ammonia selective catalytic reduction of NOx(NH₃-SCR) is considered to be one of the best technologies to control NOx emissions from fixed sources,and the key of this technology is catalyst.This paper introduces the sources of the main atmospheric pollutant NOx,the mechanism of NH₃-SCR denitration reaction and the mechanism of SO₂ poisoning of the catalyst.It focuses on the research progress of improving the sulfur resistance of Mn-Ce catalyst,aiming to provide scientific basis for the design of a new type of sulfur resistant Mn-Ce catalyst for low-temperature NH₃-SCR.

C₄ olefin is widely applied as a basic chemical raw stock in the petrochemical and polymer industries for the synthesis of special fuels,rubber,plastics,etc.Conversion of low-carbon alkanes to C₄ olefins not only effectively alleviates the shortage of low-carbon olefins in China,but also greatly increases the added value of low-carbon alkanes.This paper reviews the current status and research progress on butane catalytic dehydrogenation technology both domestically and internationally in recent years.The mechanism of n-butane dehydrogenation reaction,the effects of catalyst active components,supports,and additives on catalytic dehydrogenation performance and the reasons for deactivation of dehydrogenation catalysts are summarized.The research prospects of butane dehydrogenation process and catalysts are prospected.

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.

Dibenzyl oxalate,as a common intermediate in organic synthesis of daily and industrial products,has been widely used in the production of pharmaceuticals,dyes,pesticides,rubber products and other substances.Effects of [(PS)₄HMT][HSO₄]₄ on catalytic synthesis of dibenzyl oxalate were investigated using oxalate and benzyl alcohol as raw material,cyclohexane as water-carrying agent.The optimum reaction conditions determined by orthogonal experiments were catalyst dosage was 11% mass fraction of oxalate (11% mass fraction of oxalate after optimization),molar ratio of oxalate and benzyl alcohol was 2.3∶1,dosage of cyclohexane was 20 mL,reaction temperature was 100 ℃,and reaction time was 40 min.Ionic liquid was ionic immobilized to be stable and easily recoved.The results showed that ionic liquid performance was increased and could be separated conveniently from product after immobilization.Activity of recovered immobilized ionic liquid was stable after 6 times of circle.

Deactivation and regeneration of Raney Cu catalysts for dimethyl oxalate(DMO) selective hydrogenation to ethylene glycol(EG) were investigated by TG-DTG,XRD and FT-IR.The cycle life of situ regenerated catalyst was also tested.It was found that the main reason for rapid reversible deactivation was carbon deposition on surface active sites instead of migration and sintering of Cu nanoparticles.Surface carbon deposition could be removed by thermal treatment at temperature above 300℃.Under the optimum reaction conditions,conversion of DMO was 100%,and yield of EG was 95.0%.Nonetheless,the cycle life of catalyst became gradually shortened.Additionally,CuC₂O₄ formation on surface,the structure evolution and accessible active species irreversible loss due to pyrolysis of the copper active compounds during the DMO hydrogenation reaction further aggravated the Raney Cu catalyst deactivation.

In recent years,the application of methyl tert-butyl ether (MTBE) has been limited due to the popularization of ethanol gasoline.Isobutene,as one of its raw materials,has to find another way out.Selective oligomerization to produce high-octane isobutylene dimers is a reasonable way to make use of the large amount of mixed isobutene in C₄ produced by catalytic cracking and steam cracking.Here,HZSM-5 was modified with Ni as additive.The effect of Ni loading on the catalytic performance was investigated and a series of catalysts were characterized.The results showed that the comprehensive effect was the best with the Ni loading was 0.25%(mass fraction),and the C₈⁼ yield is 45.4%.The characterization results showed that the ratio of Lewis acid (LA) and Brönsted acid (BA) of the strong acid sites of HZSM-5 was increased after Ni modification,which played an important role in improving the C₈⁼ selectivity.The LA centers may be derived from NiAl₂O₄ generated by the interaction between Ni species and aluminum in HZSM-5.

Pd-Cu/Al₂O₃ and Pd-Cu-N/Al₂O₃ catalysts were prepared by co-impregnation method with Al₂O₃ as supports.The effect of nitrogen doping on the catalytic performance of Pd-Cu/Al₂O₃ catalyst for CO preferential oxidation in H₂-rich stream was studied by using a fixed-bed continuous flow reactor.The catalysts were characterized by XRD,FT-IR,H₂-TPR and XPS.Compared with Pd-Cu/Al₂O₃,Pd-Cu-N/Al₂O₃ has better CO preferential oxidation performance.The results show that nitrogen doping promotes the dispersion of Cu₂Cl(OH)₃ on the surface,enhances the interaction between Pd and Cu,and improves the redox ability of Pd and Cu₂Cl(OH)₃.At the same time,the addition of nitrogen is also conducive to the formation of more active Cu⁺ on the surface,and the interstitial nitrogen entering the lattice of Pd may inhibit the formation of PdHx in the reaction process,thus improving the catalytic activity of the Pd-Cu/Al₂O₃.