MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the...MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the roles of nickel, ZnO and MnOx were investigated. The results show that nickel provided a new pathway of glucose to sorbitol and played an important role in the hydrogenation of C3 intermediates to 1,2-propanediol(1,2-PDO). The high yield of 1, 2-PDO was attributed to effective C–C bond cleavage performance of ZnO support promoted by MnOx. ZnO and MnOx contribute to the conversion of glycerol to lactic acid(LA) and LA to 1, 2-PDO, respectively. A concise pathway for hydrogenation of glucose over Ni-based catalyst was proposed.展开更多
Copper-based catalysts were widely used in the heterogeneous selective hydrogenation of ethylene carbonate(EC),a key step in the indirect conversion of CO_(2) to methanol.However,a high H_(2)/EC molar ratio in feed is...Copper-based catalysts were widely used in the heterogeneous selective hydrogenation of ethylene carbonate(EC),a key step in the indirect conversion of CO_(2) to methanol.However,a high H_(2)/EC molar ratio in feed is required to achieve favorable activity and the methanol selectivity still needs to be improved.Herein,we fabricated a series of Pt-modulated Cu/SiO_(2) catalysts and investigated their catalytic performance for hydrogenation of EC in a fixed bed reactor.By modulating the Pt amount,the optimal 0.2Pt-Cu/SiO_(2) catalyst exhibited the highest catalytic performance with99%EC conversion,over 98%selectivity to ethylene glycol and 95.8%selectivity to methanol at the H_(2)/EC ratio as low as 60 in feed.In addition,0.2Pt-Cu/SiO_(2) catalyst showed excellent stability for 150 h on stream over different H_(2)/EC ratios of 180-40.It is demonstrated a proper amount of Pt could significantly lower the H_(2)/EC molar ratio,promote the reducibility and dispersion of copper,and also enhance surface density of Cu+species.This could be due to the strong interaction of Cu and Pt induced by formation of alloyed Pt single atoms on the Cu lattice.Meanwhile,a relatively higher amount of Pt would deteriorate the catalytic activity,which could be due to the surface coverage and aggregation of active species.These findings may enlighten some fundamental insights for further design of Cu-based catalysts for the hydrogenation of carbon–oxygen bonds.展开更多
Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silic...Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.展开更多
Copper supported over silica exhibited very high activity and selectivity for the direct synthesis of indole at atmospheric pressure. Under the reaction temperature of 325C,the yield of indole could obtain 88%.
基金financially supported by the National Science Foundation of China (21671132)Shanghai Science and Technology Committee(16dz1207200)the Youth Innovation Promotion Association CAS(2015231)
文摘MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the roles of nickel, ZnO and MnOx were investigated. The results show that nickel provided a new pathway of glucose to sorbitol and played an important role in the hydrogenation of C3 intermediates to 1,2-propanediol(1,2-PDO). The high yield of 1, 2-PDO was attributed to effective C–C bond cleavage performance of ZnO support promoted by MnOx. ZnO and MnOx contribute to the conversion of glycerol to lactic acid(LA) and LA to 1, 2-PDO, respectively. A concise pathway for hydrogenation of glucose over Ni-based catalyst was proposed.
基金supported by the National Natural Science Foun-dation of China(22022811,U21B2096 and 21938008)the National Key Research&Development Program of China(2018YFB0605803).
文摘Copper-based catalysts were widely used in the heterogeneous selective hydrogenation of ethylene carbonate(EC),a key step in the indirect conversion of CO_(2) to methanol.However,a high H_(2)/EC molar ratio in feed is required to achieve favorable activity and the methanol selectivity still needs to be improved.Herein,we fabricated a series of Pt-modulated Cu/SiO_(2) catalysts and investigated their catalytic performance for hydrogenation of EC in a fixed bed reactor.By modulating the Pt amount,the optimal 0.2Pt-Cu/SiO_(2) catalyst exhibited the highest catalytic performance with99%EC conversion,over 98%selectivity to ethylene glycol and 95.8%selectivity to methanol at the H_(2)/EC ratio as low as 60 in feed.In addition,0.2Pt-Cu/SiO_(2) catalyst showed excellent stability for 150 h on stream over different H_(2)/EC ratios of 180-40.It is demonstrated a proper amount of Pt could significantly lower the H_(2)/EC molar ratio,promote the reducibility and dispersion of copper,and also enhance surface density of Cu+species.This could be due to the strong interaction of Cu and Pt induced by formation of alloyed Pt single atoms on the Cu lattice.Meanwhile,a relatively higher amount of Pt would deteriorate the catalytic activity,which could be due to the surface coverage and aggregation of active species.These findings may enlighten some fundamental insights for further design of Cu-based catalysts for the hydrogenation of carbon–oxygen bonds.
文摘Methyl glycolate is a good solvent and can be used as feedstock for the synthesis of some important organic chemicals. Catalytic hydrogenation of dimethyl oxalate （DMO） over copper-silver catalyst supported on silica was studied. The Cu-Ag/SiO2 catalyst supported on silica sol was prepared by homogeneous deposition-precipitation of the mixture of aqueous euprammonia complex and silica sol. The proper active temperature of Cu-Ag/SiO2 catalyst for hydrogenation of DMO was 523-623 K. The most preferable reaction conditions for methyl glycolate （MG） were optimized： temperature at 468-478 K, 40-60 mesh catalyst diameter, H2/DMO ratio 40, and 1.0 h^-1 of LHSV.
文摘Copper supported over silica exhibited very high activity and selectivity for the direct synthesis of indole at atmospheric pressure. Under the reaction temperature of 325C,the yield of indole could obtain 88%.
