The structures and catalytic performances of V_2O_5, Mg_3V_2O_8 and V/MgO catalysts have been correlated by means of XRD, FTIR, TPR and flow micro-reactor tests. The postulation about active site has been made. Based ...The structures and catalytic performances of V_2O_5, Mg_3V_2O_8 and V/MgO catalysts have been correlated by means of XRD, FTIR, TPR and flow micro-reactor tests. The postulation about active site has been made. Based on it, better catalysts have been first prepared via grafting and modification with Sb which are better than that via impregnation.展开更多
Oxidative dehydrogenation of propane over V-Mg-O and MCl_n(M=Cu^+,Li^+, Ag^+,Cd^(2+))promoted V-Mg-O catalysts was studied.XRD result showed that the V-Mg-O catalysts were composed of MgO and Mg_3(VO_4)_2.The yield of...Oxidative dehydrogenation of propane over V-Mg-O and MCl_n(M=Cu^+,Li^+, Ag^+,Cd^(2+))promoted V-Mg-O catalysts was studied.XRD result showed that the V-Mg-O catalysts were composed of MgO and Mg_3(VO_4)_2.The yield of propene was much higher over CuCl and LiCl promoted VMgO catalysts than that over VMgO catalysts at the same reaction temperature.The highest yield of propene reached 23.1% at 500℃ and 6000h^(-1) space velocity.展开更多
The relations between catalytic activities and compositions of the systems Mg_xZn_(1-x)Fe_2O_4, Co_xZn_(1-x)Fe_2O_4, Co_xMg_(1-x)Fe_2O_4, Cd_xZn_(1-x)Fe_2O_4 and Mg_xZn_(1-x)Fe_2O_4·0.17Fe_2O_3 have been studied ...The relations between catalytic activities and compositions of the systems Mg_xZn_(1-x)Fe_2O_4, Co_xZn_(1-x)Fe_2O_4, Co_xMg_(1-x)Fe_2O_4, Cd_xZn_(1-x)Fe_2O_4 and Mg_xZn_(1-x)Fe_2O_4·0.17Fe_2O_3 have been studied by flow differential reactor, XRD, and derivative IR techniques. It has been found that the appropriate normal-inverse spinel combination substantially increases the activity for the title raction. The structure of the active site and the role of the bivalent cation in the title catalyst have been inferred.展开更多
At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of metha...At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of methane was investigated. Experimental results have revealed that the synergism does exist, when positive corona within a suitable power range and an intermediate pulse repetition frequency (PRF) for a loaded 7-Mn2O3/7-A12O3 catalyst were chosen. In respect to the mechanism approach, a tentative model for general pathway was proposed to explain the role of plasma and catalyst partaking in the process of methane decomposition and C2 products formation.展开更多
A series ofnanosized cobalt oxide catalysts modified with phosphorus have been synthesized by the solgel method and investigated in the oxidative dehydrogenation of propane to propene. With the addition of phosphorus,...A series ofnanosized cobalt oxide catalysts modified with phosphorus have been synthesized by the solgel method and investigated in the oxidative dehydrogenation of propane to propene. With the addition of phosphorus, the crystallite size of the catalyst was largely decreased, while the P species in the catalyst were highly dispersed. Compared to pure cobalt oxide, the P-modified samples showed higher propane conversion and enhanced propene selectivity. Over the PCoO catalyst with a P/Co atomic ratio of 0.05, the maximal propene yields of 15.7% with a propane conversion of 28.3% were obtained at 520 ℃.展开更多
Ammonia borane(NHsBH3,AB)is an ideal raw material of hydrogen production with higher hydrogen storage capacity.In this paper,the catalytic processes of AB dehydrogenation were described from different ways,including t...Ammonia borane(NHsBH3,AB)is an ideal raw material of hydrogen production with higher hydrogen storage capacity.In this paper,the catalytic processes of AB dehydrogenation were described from different ways,including thermal dehydrogenation,hydrolysis,methanolysis,photocatalysis and photopiezoelectric synergy catalysis with experimental research and theoretical calculations.Catalyst models include bulk materials,two-dimensional materials,nanocluster particles and single/diatomic structures.Among them,the proportion of H2 released is different,and the reaction conditions are also different,which are suitable for different application scenarios.Through this review,we could have a preliminary comprehensive understanding of AB dehydrogenation reaction.展开更多
Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized ...Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized polyolefin materials, First, pyridine-diimine cobalt-catalyzed dehydrogenative silylations of various terminal olefins with alkylsilanes lead to the formation of a variety of allylsilanes at high yields, Then, the allylsilanes are copolymerized with ethylene using an α-diimine nickel catalyst, leading to the formation of branched polyolefins with high molecular weight and moderate comonomer incorporation. This subsequent catalytic process is an efficient strategy for the synthesis of silicon-functionalized polyolefins using widely available and inexpensive starting materials.展开更多
文摘The structures and catalytic performances of V_2O_5, Mg_3V_2O_8 and V/MgO catalysts have been correlated by means of XRD, FTIR, TPR and flow micro-reactor tests. The postulation about active site has been made. Based on it, better catalysts have been first prepared via grafting and modification with Sb which are better than that via impregnation.
文摘Oxidative dehydrogenation of propane over V-Mg-O and MCl_n(M=Cu^+,Li^+, Ag^+,Cd^(2+))promoted V-Mg-O catalysts was studied.XRD result showed that the V-Mg-O catalysts were composed of MgO and Mg_3(VO_4)_2.The yield of propene was much higher over CuCl and LiCl promoted VMgO catalysts than that over VMgO catalysts at the same reaction temperature.The highest yield of propene reached 23.1% at 500℃ and 6000h^(-1) space velocity.
基金Project supported by National Natural Science Foundation of P. R. China.
文摘The relations between catalytic activities and compositions of the systems Mg_xZn_(1-x)Fe_2O_4, Co_xZn_(1-x)Fe_2O_4, Co_xMg_(1-x)Fe_2O_4, Cd_xZn_(1-x)Fe_2O_4 and Mg_xZn_(1-x)Fe_2O_4·0.17Fe_2O_3 have been studied by flow differential reactor, XRD, and derivative IR techniques. It has been found that the appropriate normal-inverse spinel combination substantially increases the activity for the title raction. The structure of the active site and the role of the bivalent cation in the title catalyst have been inferred.
文摘At atmospheric pressure and ambient temperature, pulse corona induced plasma was used as a new method for dehydrogenative coupling of methane. The synergism of plasma and catalyst on dehydrogenative coupling of methane was investigated. Experimental results have revealed that the synergism does exist, when positive corona within a suitable power range and an intermediate pulse repetition frequency (PRF) for a loaded 7-Mn2O3/7-A12O3 catalyst were chosen. In respect to the mechanism approach, a tentative model for general pathway was proposed to explain the role of plasma and catalyst partaking in the process of methane decomposition and C2 products formation.
基金supported by the National Basic Research Program of China(Nos.2010CB732303 and 2013CB933102)the National Natural Science Foundation of China(Nos.21073148 and 21033006)the Program for Innovative Research Team of the Ministry of Education of China(No.IRT1036)
文摘A series ofnanosized cobalt oxide catalysts modified with phosphorus have been synthesized by the solgel method and investigated in the oxidative dehydrogenation of propane to propene. With the addition of phosphorus, the crystallite size of the catalyst was largely decreased, while the P species in the catalyst were highly dispersed. Compared to pure cobalt oxide, the P-modified samples showed higher propane conversion and enhanced propene selectivity. Over the PCoO catalyst with a P/Co atomic ratio of 0.05, the maximal propene yields of 15.7% with a propane conversion of 28.3% were obtained at 520 ℃.
基金funded by the Natural Science Basic Research Program of Shaanxi(Nos.2022JQ-108 and 2022JQ-096)the National Natural Science Foundation of China(No.22104079).
文摘Ammonia borane(NHsBH3,AB)is an ideal raw material of hydrogen production with higher hydrogen storage capacity.In this paper,the catalytic processes of AB dehydrogenation were described from different ways,including thermal dehydrogenation,hydrolysis,methanolysis,photocatalysis and photopiezoelectric synergy catalysis with experimental research and theoretical calculations.Catalyst models include bulk materials,two-dimensional materials,nanocluster particles and single/diatomic structures.Among them,the proportion of H2 released is different,and the reaction conditions are also different,which are suitable for different application scenarios.Through this review,we could have a preliminary comprehensive understanding of AB dehydrogenation reaction.
基金supported by the National Natural Science Foundation of China(21690071 and 51522306)
文摘Metal catalyzed olefin hydrosilylation and metal mediated olefin polymerization are both of great academic and industrial importance, In this article, these two aspects are combined to prepare silicon- functionalized polyolefin materials, First, pyridine-diimine cobalt-catalyzed dehydrogenative silylations of various terminal olefins with alkylsilanes lead to the formation of a variety of allylsilanes at high yields, Then, the allylsilanes are copolymerized with ethylene using an α-diimine nickel catalyst, leading to the formation of branched polyolefins with high molecular weight and moderate comonomer incorporation. This subsequent catalytic process is an efficient strategy for the synthesis of silicon-functionalized polyolefins using widely available and inexpensive starting materials.