An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,c...An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes.The conversion of nitrobenzene can reach 3170 molconv h^–1 molPt^–1 under mild conditions(30°C,5 bar),which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions.The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity,which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles.The unique surface properties ofα-Fe2O3 play an important role in the reaction process.It provides active sites for hydrogen spillover and reactant adsorption,and ultimately completes the hydrogenation of the nitro group on the catalyst surface.展开更多
Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxid...Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxidation of As(Ⅲ) to As(V) is considered to be an effective means to reduce the toxicity of arsenic and to promote the removal efficiency of arsenic. Due to their high catalytic activity and arsenic affinity, iron-based functional materials can quickly oxidize As(Ⅲ) to As(V) in heterogeneous Fenton-like systems, and then remove As(V) from water through adsorption and surface coprecipitation. In this review, the effects of different iron-based functional materials such as zero-valent iron and iron(hydroxy) oxides on arsenic removal are compared, and the catalytic oxidation mechanism of As(Ⅲ) in heterogeneous Fenton process is further clarified. Finally, the main challenges and opportunities faced by iron-based As(Ⅲ) oxidation functional materials are prospected.展开更多
Direct oxidative coupling of an alcohol and amine,with air or molecular oxygen as the oxygen source,is an environmentally friendly method for imine synthesis.We developed an Fe catalyst supported on mesoporous carbon...Direct oxidative coupling of an alcohol and amine,with air or molecular oxygen as the oxygen source,is an environmentally friendly method for imine synthesis.We developed an Fe catalyst supported on mesoporous carbon（denoted by FeOx/HCMK-3） for this reaction with excellent activity and recyclability.FeOx/HCMK-3 was prepared by impregnating HNO3-treated mesoporous carbon（CMK-3） with iron nitrate solution.The highly dispersed FeOx species give FeOx/HCMK-3 high reducibility and are responsible for the high catalytic performance.Imine synthesis over FeOx/HCMK-3 follows a redox mechanism.The oxygen species in FeOx/HCMK-3 participate in the reaction and are then regenerated by oxidation with molecular O2.The reaction involves two consecutive steps：oxidative dehydrogenation of an alcohol to an aldehyde and coupling of the aldehyde with an amine to give an imine.Oxidative dehydrogenation of the alcohol is the rate-determining step in the reaction.展开更多
Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to ...Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to investigate its performance of hydrogen-rich gas production. The effects of reaction temperature, catalyst and flow rate on gas concentrations （volume fraction）, hydrogen yield, DME conversion ratio, specific energy consumption and thermal efficiency were investigated, respectively. The experimental results show that hydrogen concentration and the flow rate of produced H2 are improved when temperature increases from 300 ℃ to 700 ℃. Hydrogen yield, hydrogen concentration and the flow rate of produced H2 are substantially improved in the use of Fe-based catalyst at high temperature. Moreover, hydrogen yield and thermal efficiency are improved and change slightly when flow rate increases. When catalyst is 12 g, and flow rate increases from 35 mL/min to 210 mL/min, hydrogen yield decreases from 66.4% to 57.7%, and thermal efficiency decreases from 35.6% to 30.9%. It is anticipated that the results would serve as a good guideline to the application of hydrogen generation from hydrocarbon fuels by plasma reforming onboard.展开更多
Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the expe...Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.展开更多
基金supported by the National Natural Science Foundation of China(21473073,21473074)‘‘13th Five-Year’’ Science and Technology Research of the Education Department of Jilin Province(2016403)+1 种基金the Development Project of Science and Technology of Jilin Province(20170101171JC,20180201068SF)the Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry(201703)~~
文摘An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors andα-Fe2O3 as a support.The catalyst with Pt content as low as 0.2 wt%exhibits high activities,chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes.The conversion of nitrobenzene can reach 3170 molconv h^–1 molPt^–1 under mild conditions(30°C,5 bar),which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions.The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity,which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles.The unique surface properties ofα-Fe2O3 play an important role in the reaction process.It provides active sites for hydrogen spillover and reactant adsorption,and ultimately completes the hydrogenation of the nitro group on the catalyst surface.
基金financially supported by the National Science Fund for Excellent Young Scholars of China (No. 52022111)the Distinguished Young Scholars of China (No. 51825403)the National Natural Science Foundation of China (Nos. 51634010, 51974379)。
文摘Between the two major arsenic-containing salts in natural water, arsenite(As(Ⅲ)) is far more harmful to human and the environment than arsenate(As(V)) due to its high toxicity and transportability. Therefore, preoxidation of As(Ⅲ) to As(V) is considered to be an effective means to reduce the toxicity of arsenic and to promote the removal efficiency of arsenic. Due to their high catalytic activity and arsenic affinity, iron-based functional materials can quickly oxidize As(Ⅲ) to As(V) in heterogeneous Fenton-like systems, and then remove As(V) from water through adsorption and surface coprecipitation. In this review, the effects of different iron-based functional materials such as zero-valent iron and iron(hydroxy) oxides on arsenic removal are compared, and the catalytic oxidation mechanism of As(Ⅲ) in heterogeneous Fenton process is further clarified. Finally, the main challenges and opportunities faced by iron-based As(Ⅲ) oxidation functional materials are prospected.
基金supported by the National Natural Science Foundation of China(21473073,21473074)the "13th Five-Year" Science and Technology Research of the Education Department of Jilin Province(2016403)~~
文摘Direct oxidative coupling of an alcohol and amine,with air or molecular oxygen as the oxygen source,is an environmentally friendly method for imine synthesis.We developed an Fe catalyst supported on mesoporous carbon（denoted by FeOx/HCMK-3） for this reaction with excellent activity and recyclability.FeOx/HCMK-3 was prepared by impregnating HNO3-treated mesoporous carbon（CMK-3） with iron nitrate solution.The highly dispersed FeOx species give FeOx/HCMK-3 high reducibility and are responsible for the high catalytic performance.Imine synthesis over FeOx/HCMK-3 follows a redox mechanism.The oxygen species in FeOx/HCMK-3 participate in the reaction and are then regenerated by oxidation with molecular O2.The reaction involves two consecutive steps：oxidative dehydrogenation of an alcohol to an aldehyde and coupling of the aldehyde with an amine to give an imine.Oxidative dehydrogenation of the alcohol is the rate-determining step in the reaction.
基金Project(21106002)supported by the National Natural Science Foundation of ChinaProject(2010DFA72760)supported by the Collaboration on Cutting-Edge Technology Development of Electric Vehicle,China
文摘Hydrogen was produced from partial oxidation reforming of DME （dimethyl ether） by spark discharge plasma at atmospheric pressure. A plasma-catalyst reformer was designed. A series of experiments were carried out to investigate its performance of hydrogen-rich gas production. The effects of reaction temperature, catalyst and flow rate on gas concentrations （volume fraction）, hydrogen yield, DME conversion ratio, specific energy consumption and thermal efficiency were investigated, respectively. The experimental results show that hydrogen concentration and the flow rate of produced H2 are improved when temperature increases from 300 ℃ to 700 ℃. Hydrogen yield, hydrogen concentration and the flow rate of produced H2 are substantially improved in the use of Fe-based catalyst at high temperature. Moreover, hydrogen yield and thermal efficiency are improved and change slightly when flow rate increases. When catalyst is 12 g, and flow rate increases from 35 mL/min to 210 mL/min, hydrogen yield decreases from 66.4% to 57.7%, and thermal efficiency decreases from 35.6% to 30.9%. It is anticipated that the results would serve as a good guideline to the application of hydrogen generation from hydrocarbon fuels by plasma reforming onboard.
基金Sponsored by the National Natural Science Foundation of China(Grant No.20271019 and 20576027), Natural Science Foundation of Heilongjiang Prov-ince(Grant No.B200504), Postdoctoral Foundationof Heilongjiang Province(Grant No.LBH-Z05066) and Education Department Foundation of Hei-longjiang Province(Grant No.11511270).
文摘Iron-based perovskite-type compounds modified by Ru were prepared through sol-gel process to study its catalytic activity of NOx direct decomposition at low temperature and evaluate the conversion of NO under the experimental conditions. The catalytic activity of La 0.9Ce 0.1Fe 0.8-nCo 0.2RunO3 （n=0.01,0.03,0.05,0.07,0.09）series for the NO, NO-CO two components, CO-HC-NO three components were also analyzed. The catalytic investigation evidenced that the presence of Ru is necessary for making highly activity in decomposition of nitric oxide even at low temperature（400 ℃）and La 0.9Ce 0.9Fe 0.75Co 0.2Ru 0.05O3 （n=0.05） has better activity in all the samples, the conversion of it is 58.5%. With the reducing gas（CO,C3H6）added into the gas, the catalyst displayed very high activity in decomposition of NO and the conversion of it is 80% and 92.5% separately.
