With the rise of green chemistry,green low pollution and pollution-free solvents have attracted much attention.Deep Eutectic Solvents are considered as a new type of green solvents for ionic liquids,which have the advantages of low saturated vapor pressure,low melting point,non-toxic and environmental protection,degradability and low price,etc.The composition and types,preparation methods, physical and chemical properties(such as melting point,viscosity,surface tension,etc.) of deep eutectic solvents,as well as their applications in extraction and separation,biochemistry,electrochemistry,and other fields were reviewed.The current problems in the application of deep eutectic solvents and looks forward to future research directions were summarized.

Reverse water gas shift (RWGS) reaction,acting as a key step to convert carbon dioxide into chemicals or hydrocarbon,is of great significance for the utilization of carbon dioxide resources.In this paper,the thermodynamic analysis,reaction mechanism and the research progress of catalysts used in RWGS in recent ten years are reviewed.It is concluded that the Cu-based catalysts have the advantages of low-cost,high activity and high CO selectivity.However,Cu-based catalysts are easier to deactivate by coking and tend to sinter at high temperature,leading to a decrease of catalyst stability.At present,researchers are mainly focused on the aspects of regulation of Cu active centers and optimization of process conditions.In the aspect of regulation of Cu active center,it mainly includes:①modification of the structural characteristics of Cu sites,such as dispersion,particle size;②addition of promoters,including alkali metals (Na、K) and transition metals (Fe、Ce、Co);③introduction of proper support,such as Al₂O₃,Mo₂C,CeO₂ to enhance the metal-support interaction.In terms of optimization of process conditions,both CO selectivity and CO₂ conversion can be enhanced by changing reaction temperature,pressure and adjusting H₂/CO₂ molar ratio in RWGS reaction.Finally,it is proposed that the coupling of CO₂ with some important hydrogen production reactions such as light alkanes dehydrogenation,aromatization of methanol can achieve the purpose of increasing target products and reducing CO₂ emission based on RWGS reaction.

The hydroisomerization of alkanes plays an increasingly important role in the chemical industry.However,due to the complex synergistic effect between the metal and acid sites on bifunctional catalysts,preparing catalysts with excellent hydroisomerization performance remains a challenge.To further improve the performance of the catalyst,it is necessary to optimize the equilibrium relationship between metal sites and acid sites,and a good metal acid equilibrium state helps to improve the selectivity of isomeric products in the catalyst.This review first introduces the bifunctional mechanism in the hydroisomerization of alkanes,and then summarizes the relevant research results of metal-acid balance between metal sites and acid sites in this catalytic system in recent years from two aspects:concentration balance and distance balance.Finally,some modification methods for optimizing the metal-acid balance of catalysts are exampled.

Resorcinol formaldehyde resin was synthesized from resorcinol,styrene and formaldehyde.Effects of catalyst and reaction conditions on properties of resin were investigated.The results showed that resorcinol formaldehyde resin with softening point of 109 ℃ could be prepared by using p-toluenesulfonic acid as catalyst and adjusting the reaction conditions such as the amount of substances.The vulcanized rubber prepared with resorcinol formaldehyde resin has the same vulcanization and physical properties as the vulcanized rubber prepared with resorcinol,which meets the needs of current radial tire adhesion.

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.

Carbon monoxide(CO) is widely existed in industrial furnace and coking waste gases,and boiler combustion gas.The development of high-efficiency at low temperature,low-cost,high-tolerability catalysts for CO oxidation elimination can bring higher environmental and economic benefits.This review covered the research progress on catalysts for CO oxidation elimination,and discussed the effects of metal composition,support,preparation method on the catalyst activity and tolerability.Various typical precious metal and non-precious metal catalysts are summarized,and the development of catalytic oxidation of CO was prospected.

In this paper,microporous-mesoporous HZSM-5/MCM-41 composites with micro and nano-sized were prepared using HZSM-5 as raw material.The effects of the reaction pressure on the conversion and products selectivity in n-decane catalytic cracking reaction were investigated.It is found that when the system pressure is low,the density of the reaction fluid increases with the increase of the system pressure,promoting the aromatization of light olefins into aromatics and decreasing the selectivity of light olefins.When the pressure further increases,most of the cracking products are in a near critical or supercritical state,which reduces the aromatization degree of light olefins and increases light alkanes content.

In order to find out the evolution law of Huangjiu lees during pyrolysis and carbonization,the relationship between mass loss of Huangjiu lees and temperature was studied by thermogravimetric anal-ysis.Then,the pyrolysis product was characterized by elemental composition analysis,Boehm titration and Fourier transform infrared spectroscopy (FT-IR).The decomposition of Huangjiu lees during pyrolysis was mainly focused on (250-500) ℃ with the most intense pyrolysis at (300-370) ℃.The predominant reaction of Huangjiu lees carbonization at (220-300) ℃ was dehydration,and deoxygenation at (300-370) ℃,such as decarbonylation,decarboxylation,and ether bond cleavage reaction,etc.The predominant carbonization reaction shifted from deoxygenation toward dehydrogenation at (370-500) ℃,such as demethylation and demethylenation.Meanwhile,the content of aliphatic hydrocarbons in the product decreased gradually and that of the aromatic structure increased.The predominant carbonization was condensation at exceeded 500 ℃.The aromaticity of product increased with temperature and condensed aromatic structures emerged highly in the product.The specific surface area of Huangjiu lees-based biochar activated by ZnCl₂ was 1 155 m²·g^-1,which could be used as catalyst carrier.

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.

Hydrogenolysis debenzylation reaction is considered as a key process in organic synthesis field.However,the use of precious Pd metal and its inevitable loss greatly increase the cost of product.Therefore,developing hydrogenolysis catalysts with high performance,long life and low cost is regarded as the core technology to improve the product competitiveness.Among various alternative strategies,Pd-based alloy catalysts becomes a more potential scheme due to the synergistic effect,better stability and partial substitution with non-noble metals.Herein,this review summarizes recent progress of Pd-based alloy catalysts for hydrogenolysis debenzylation reaction based on the mechanism,then discusses the design principle,preparation method and alloy effect of Pd-based alloy catalysts.Finally,the design,preparation,application and recycle of Pd-based alloy catalysts are summarized and given an outlook from the perspective of industrialized hydrogenolysis debenzylation reaction.

The value-added conversion of renewable platform molecules to advanced fuels and fine chemicals is a promising strategy for meeting future sustainability needs.Because carbon-based nanocatalysts have good electronic and geometric properties,they have a strong ability to enhance catalyst activity and stability.The regular and uniform structure make it possible to explore their intrinsic reaction mechanisms and provide a site for the value-added conversion of renewable platform molecules to advanced fuels and chemicals.Heteroatom doping can effectively solve the problem of weak interaction force between unmodified carbon materials and metal and easy agglomeration deactivation,and can change the inherent special properties of carbon carriers,which provides the possibility of customized carbon catalysts for specific catalytic reactions.The research progress on heteratomic-doped carbon-based nano-metal catalysts is discussed,mainly involving the doping of nitrogen,boron,phosphorus,sulfur and other elements,and the application in catalytic conversion of renewable platform molecules.These methods for the regulation of catalyst properties conducive to the understanding of the structure-property relationship of carbon-based catalysts.Finally,the challenges and potential applications of carbon-based nanocatalysts are also discussed.

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.

A series of Nb-doped V-Mo-Ti catalysts were prepared by impregnation method.The influence of V₂O₅ load and Nb doping on the low-temperature denitration activity of the catalyst was investig-ated,and the decomposition performance of catalyst in ammonium hydrogen sulfate was explored.The cata-lysts were characterized by using XRD,N₂ adsorption-desorption,H₂-TPR,NH₃-TPD and IR.The results show that Nb doping promotes the redox performance and improves the surface acidity of the catalyst,which makes the catalyst having more excellent denitrification performance at low temperature.Under the GHSV of 5 000 h^-1,the denitrification efficiency of 1.5Nb-6V-3Mo-Ti catalyst reaches 100% at 180 ℃.At the same time,Nb doping improves the NO oxidation capacity of the catalyst and promotes the reaction of ammonia hydrogen sulfate and NO,thus improving the water-sulfur toxicity resistance of the catalyst at low temperature.

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.

The nickel based catalysts used for methane reforming are prone to sintering and deactivation at high temperatures,and catalyst stability has always been a focus of research.Magnesium aluminum spinel materials have good high-temperature stability and are not easily sintered at high temperatures,therefore they have good industrial application prospects.The preparation methods of nickel based catalysts with magnesium aluminum spinel structure (including stepwise impregnation,co-precipitation,solvent evaporation self-assembly,sol-gel method,hydrothermal synthesis and flame jet pyrolysis) and their effects on the structure and performance of the catalysts were reviewed.This article introduces the research progress on the stability of magnesium aluminum spinel catalysts for methane reforming.This article introduces the influence of the combination of magnesium aluminum spinel materials and limited functional materials on the structure and performance of catalysts,summarizes the problems existing in magnesium aluminum spinel nickel based methane reforming catalysts,and envisions their application prospects.

With the continuous progress of polymerization process,the variety of polymer macromolecules containing unsaturated double bonds is becoming more and more abundant,and the hydrogenation modification of them is also becoming more and more important.The research progress of polymer hydrogenation catalysts,including Ziegler-Natta catalysts(Z-N catalysts),metallocene catalysts,noble metal complex cata-lysts,and non-homogeneous catalysts,is reviewed.The catalytic mechanism of the catalysts and factors affecting the catalytic activity are summarized,and the direction of their development is prospected.

The air pollution caused by sulfur-containing compounds in liquid fuels (especially diesel and gasoline) has become a hot topic of concern in all walks of life.Green fuel is very important for sustainable development and clean environment.Effective and complete removal of sulfur compounds from fuel oil is the technical key to prepare a new catalytic desulfurization catalyst.In this paper,the application and research of molecular sieve in the field of catalytic desulfurization are reviewed,the existing main molecular sieve catalytic desulfurization technologies are summarized and analyzed,the mechanism of zeolites in desulfurization process is emphatically discussed,the application status of molecular sieve catalytic desulfurization in petroleum processing field is expounded,and its development prospect is prospected.

Nitrogen oxides (NO_x) are important precursors of haze,acid rain and ozone,and flue gas denitrification of stationary sources such as coal-fired power plants and mobile sources such as diesel vehicles is imminent.Ammonia selective catalytic reduction (NH₃-SCR) is currently the most effective flue gas/exhaust denitrification technology.In order to meet NO_x emission standards,NH₃-SCR catalysts need to have efficient denitrification activity and stability over a wide temperature range.Rare earth materials have a wide range of applications in denitrification due to their unique electronic structure,adjustable surface acidity and redox properties.The latest research progress of medium-low and medium-high temperature rare earth-based metal oxide SCR denitrification catalysts,the preparation methods of molecular sieve SCR denitrification catalysts,including ion exchange method,one-pot method and green synthesis method,are reviewed,and the current research hotspots and challenges of wide-temperature SCR catalysts are summarized.

In recent years,Co-based catalysts have been applied to propane dehydrogenation,which exhibit higher catalytic activity than traditional precious metal Pt-based catalysts,and has gradually become a research focus.The complexity of multivalent states and multiple coordination of cobalt species leads to the inconsistent understanding of its active site structure and reaction mechanism.Especially under the reaction conditions of high temperature and reducing atmosphere (propane and its derivatives),CoO_x active sites are usually partially reduced in different degrees and easily converted into highly dispersed Co²⁺ species or ultra-small metal Co,which are usually considered as efficient active sites.In this paper,the Co-based propane dehydrogenation catalysts were classified according to the different catalyst support.Effects of different coordination environments,dispersions,and valence Co species on C-H activation,propylene selectivity and catalyst stability of propane dehydrogenation were systematically summarized,which provides a certain reference for further design of efficient Co-based propane dehydrogenation catalysts.

Process and catalyst study on selective hydrogenation of isoprene to n-pentene were carried out in the article.The results show that Pd-Pb-K/γ-Al₂O₃ noble metal catalyst has good hydrogenation activity and selectivity,and the selectivity of n-pentene can be improved by strictly controlling the molar ratio of hydrogen to diolefin and hydrogen distribution in three-stage hydrogen injection process.

V-Ti oxides catalysts were prepared by impregation and calcinated at different temperature and tested in a fixed bed reactor for durene oxidation to pyromellitic dianhydride (PMDA).The physical-chemical properties of catalysts were characterized by XRD,Raman and H₂-TPR method.The results showed that the vanadium in the catalyst was mainly in the form of crystal V₂O₅ and surface VO_x species on the TiO₂.The ratio of surface VO_x species and crystal V₂O₅ in catalyst can be influenced by calcination temperature,and the higher temperature,the more V₂ {\mathrm{O}}_5 {}_{}and polymerized VO_x species it was in the catalyst.The catalyst calcinated at 500 ℃ has a highest PMDA yield of 85.8% in the reaction of durene oxidation as the reducibility was moderate and the weak acidity was more.

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.

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.

Solar photocatalytic technology is favored by researchers because of its environmentally friendly and low-cost features,and research on applying photocatalytic technology to textile field has achieved some success.Under light irradiation,semiconductor photocatalysts can degrade organic pollutants by absorbing photon energy and stimulating active radicals with strong redox ability.This paper reviews the common carriers of photocatalytic materials and their loading methods on textiles,and summarizes the special functions they can give to textiles.The study shows that photocatalytic materials have good application prospects for treating textile printing and dyeing wastewater;the fabrics treated with photocatalysts can obtain self-cleaning,anti-bacterial and anti-ultraviolet functions,which can reduce the number of washing times of textiles and effectively protect the health of human skin;loading photocatalysts onto fibers or fabrics effectively enhances their recyclability.This study lays a foundation for the future exploration of photocatalytic technology in the textile field.

{\mathrm{SO}}_4^{2-}/ZrO₂-γ-Al₂O₃ solid acid catalyst was prepared by precipitation-impregnation method.Preparation of triethylene glycol diisooctanoate(TGDE)by catalytic method using esterification reaction of triethylene glycol and 2-ethylhexanoic acid as probe reaction.The optimal conditions of preparation were performed to confirm.The results show that the optimum preparation conditions for solid acid catalyst through precipitation-impregnation method are calcination temperature is 600 ℃,the calcination time is 5 h,the sulfuric acid impregnation concentration is 0.6 mol·L^-1,the sulfuric acid impregnation time is 9 h,and the aging temperature is -20 ℃.The conversion of triethylene glycol reachs to 99.06% and still remains 90.54% after recycling 5 times at the optimum conditions.The target product TGDE was anal-yzed and detected by gas chromatography,FT-IR,¹HNMR,and ¹³CNMR,and all performance indicators met the requirements of national standards.

Mordenite possesses the unique pore structure,large specific surface area and pore volume,strong acidity and remarkable adsorption performance,along with exceptional acid resistance,hydrothermal stability,and thermal stability.It is an affordable,readily available,renewable,and eco-friendly material.Mordenite has broad application prospects in environmental fields such as water,air,and soil pollution control,as well as soil improvement.The article presents an overview of recent research and application advancements of mordenite in the field of environment in recent years,including heavy metal and nitrogen pollution control in water resources,CO₂ capture and utilization,VOCs control,soil improvement and pollution control.Meanwhile the article also envisioning future directions for mordenite improvement,aiming to drive environmental science research and practice and facilitate the achievement of environmental protection and sustainable development goals.

The morphology of semiconductor catalyst is one of the important factors affecting the efficiency of photocatalytic decomposition of aquatic hydrogen.However,the influence of sacrificial agents in the reaction system is often ignored in most researches when discussing the effect of catalyst morphology.The CdS with good visible light activity was used as the research object to prepare the samples of nanoparticles,nanorods and nanosheets,and the hydrogen production efficiency of the CdS with different morphology was compared in the reaction system with sodium sulfide/sodium sulfite mixture,lactic acid and trieth-anolamine as the sacrifice agent.The experimental results showed that the hydrogen production efficiency of CdS nanosheets was 23.86 mmol·(g·h)^-1 when sodium sulfide/sodium sulfite mixture was used as sacrificant,which was much higher than that of the other two morphology samples.When the sacrificial agent was lactic acid or triethanolamine,the hydrogen production efficiency of CdS nanorods was the highest.

A cobalt molybdenum impregnation solution was prepared using cobalt nitrate and ammonium heptamolybdate as raw materials.Tartaric acid (TA),citric acid (CA), and ethylenediamine tetraacetic acid (EDTA) were added to the impregnation solution and impregnated onto a carrier containing mesoporous silicon to prepare a series of catalysts.By characterization of N₂ adsorption-desorption,HRTEM,H₂-TPR,NH₃-TPD,etc.,it was found that the addition of a complexing agent reduced the interaction force between the active metal and the carrier,which was conducive to the formation of more Class Ⅱ active phases,with longer crystal length and more crystal layers.At the same time,it has a larger specific surface area and pore volume,and the acidity and medium strength of the acid are also increased.Therefore,catalysts with added complexing agents have higher conversion and thiol selectivity.

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.

Bismuth oxybromide (BiOBr) particles with lamellar structure was synthesized by hydrothermal synthesis.X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that BiOBr was successfully prepared,and its formation mechanism was investigated.The effect of structural changes on the photocatalytic performance of BiOBr was investigated using quinolone antibiotic norfloxacin (NOR) as a degradation substrate under xenon light illumination.The results show that the BiOBr prepared under hydrothermal conditions has a sheet-like structure.As the solution pH value increases,the size of the BiOBr becomes smaller and the dispersion becomes worse,the absorption band edge is blue-shifted,and the forbidden band width becomes larger.The growth mechanism of lamellar BiOBr in water solvent environment is obtained,and it is proved that when the pH=1,the BiOBr-1ph sample prepared as uniform lame-llar structure with a width of (3-5) μm and a band gap of 2.93 eV shows the best photocatalytic acti-vity.The degradation of NOR over the above catalyst is 87.2% after 60 min of reaction,and the best degradation rate constant is 3.31×10^-2 min^-1.

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.

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.

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.

A continuous method was used to prepare pseudo boehmite,and corresponding orthogonal experiments were designed to investigate the effect of preparation conditions on the surface hydroxyl properties of pseudo boehmite.The types and contents of surface hydroxyl groups in the obtained samples were analyzed by infrared spectroscopy and other methods.The results show that the synthesis conditions have a significant impact on the proportion of hydroxyl groups,especially the range of type Ⅲ hydroxyl groups (neutral) with the highest value 94.61% of N-4 and the lowest 31.84% of N-16.The change in hydroxyl peak area leads to varying degrees of shift in the position of the hydroxyl peak,which is generally manifested as a decrease in the 3 680 cm^-1 peak and/or 3 730 cm^-1 peak,and an increase in the 3 730 cm^-1 peak and/or 3 790 cm^-1 peak.

A method for the determination of rhodium content in 5% rhodium carbon catalyst by super microwave digestion and ICP spectroscopy was established.Through single factor experiment and orthogonal optimization,the weighing sample,acid system,digestion temperature,digestion time were investigated.The optimal digestion conditions were determined that the 0.10 g samples were stored in a closed digestion tank with 9.0 mL HNO₃ and 1.0 mL H₂O₂ as acid system,the samples were kept at 240 ℃ for 40 min.After acid removal and volume determination,the content of precious metals in the solution was determined by ICP-AES method.The method is simple and fast,the samples digestion are complete and the results are stable,the relative standard deviation is less than 1.0%.

Photocatalysis technology is the most promising technology to solve energy shortage and control environmental pollution.Carbon nitride is favored in the industry as a new type of green pollution-free semiconductor material.However,pure carbon nitride has low quantum efficiency and high photo-gener-ated carrier recombination rate,which limits the photocatalytic performance under visible light irradiation.The frequently-used modification methods include noble metal modification,ion doping and heterostructure construction.In this paper,melamine,potassium iodide,and bismuth nitrate pentahydrate are used as raw materials.The graphite phase carbon nitride (g-C₃N₄) is prepared by calcining melamine at a high temperature of 520 ℃.The n-n type g-C₃N₄/BiOI heterojunction photocatalyst was prepared by one-step co-precipitation method.The heterojunction interface greatly increases the separation efficiency of photogenerated carriers,resulting in better photocatalytic performance.Photodegradation of methyl orange (MO),methylene blue (MB) and Rhodamine B (RhB) showed that the catalyst with molar ratio of g-C₃N₄∶BiOI=1∶1 had the best photocatalytic activity.The degradation efficiency of MO,MB and RhB was almost 100%,98% and 80%,respectively.The apparent reaction rate constants were 385 times,24.3 times and 2.5 times of pure g-C₃N₄.

Four product quality improvement methods for synthesis gas to ethylene glycol are reviewed,including liquid phase hydrogenation,NaOH addition,additive agent and ion exchange resin adsorption.The action principles and effects of the four methods were discussed.The performance of hydrogenation catalyst is the basis for improvement of ethylene glycol product quality.The performance of liquid phase hydrogenation catalyst should be improved further to simplify the production process. The engineers and technicians can consult the methods of improving product quality in this paper.

The cracking reaction of methane on Xiaolongtan (XLT) lignite coal as well as on treated coal chars,including water treated coal char,HCl-HF treated coal char and nitric acid treated coal char were investigated in a small quartz tube fixed bed.The initial conversion of methane on XLT coal char was 64.7%,and the initial conversion of methane on water treated coal char and nitric acid treated coal char were significantly increased to 78.5% and 72.4%,respectively.Whereas the initial conversion of methane on HCl-HF treated coal char decreased to 54.1%,and the catalytic activity of the coal char was reduced.With the increasing reaction time,the methane cracking conversion and hydrogen yield also decreased gradually,indicating that different coal chars were gradually deactivated during the reaction process.The difference of coal chars before and after the reaction were characterized by SEM and specific surface area tester.The BET data showed that the specific surface area and microporous capacity of coal chars decreased and the average pore diameter increased after methane cracking,which was attributed to the reaction-generated carbon deposits clogging the micropores of the coal char.The SEM results showed that there was a significant generation of carbon deposits on the surface of the coal char after methane cracking,which ultimately led to the gradual decrease in the catalytic activity of the coal chars.

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.