Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR...Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR） of NO with NH3 at low-temperature were evaluated. Mn-CeOx/Ti-PILCs were characterized by X-ray diffraction, N2 adsorption, Fourier transform infrared spectroscopy, thermal analysis, temperature-programmed desorption of ammonia and H2-temperature-programmed reduction. It was found that Ti-pillar tend to be helpful for the enlargement of surface area, pore volume, acidity and the enhancement of thermal stability for Mn-CeOx/Ti-PILCs. Mn- CeOx/Ti-PILCs catalysts were active for the SCR of NO. Among three resultant Mn-CeOx/Ti-PILCs, the catalyst from TiOSO4 showed the highest activity with 98% NO conversion at 220°C, it also exhibited good resistance to H2O and SO2 in flue gas. The catalyst from TiCl4 exhibited the lowest activity due to the unsuccessful pillaring process.展开更多
The development of highly active noble-metal-flee catalysts for catalytic hydrolysis of ammonia borane is mandatory for its application in hydrogen storage. Herein, Co-CeOx nanoclusters have been successfully anchored...The development of highly active noble-metal-flee catalysts for catalytic hydrolysis of ammonia borane is mandatory for its application in hydrogen storage. Herein, Co-CeOx nanoclusters have been successfully anchored on a three-dimensional nitrogen-doped graphene hydrogel （NGH） by a simple coreduction method and further used as efficient catalysts to catalytic hydrolysis of ammonia borane at room temperature. Thanks to the strong synergistic electronic effect between Co and CeOx, as well as the strong metal-support interaction between Co-CeOx and 3D NGH, the as-synthesized Co-（CeOx）0.91/NGH catalyst exhibits superior catalytic activity toward hydrolysis of ammonia borane, with the turnover frequency （TOF） value of 79.5 min 1, which is almost 13 times higher than that of Co]NGH, and higher than most of the reported noble-metal-free catalysts.展开更多
The safe and efficient storage and release of hydrogen is one of the key technological challenges for the fuel cell-based hydrogen economy. Hydrazine monohydrate has attracted considerable attention as a safe and conv...The safe and efficient storage and release of hydrogen is one of the key technological challenges for the fuel cell-based hydrogen economy. Hydrazine monohydrate has attracted considerable attention as a safe and convent chemical hydrogen-storage material. Herein, we report the facile synthesis of NiPt-CeOx nanocomposites supported by three-dimensional nitrogen-doped graphene hydrogels （NGHs） via a simple one-step co-reduction synthesis method. These catalysts were composition-dependent for hydrogen generation from an alkaline solution of hydrazine. （NisPt5）I-（CeOx）0.B/NGH exhibited the highest catalytic activity, with 100% hydrogen selectivity and turnover frequencies of 408 h^-1 at 298 K and 3,064 h^-1 at 323 K. These superior catalytic performances are attributed to the electronic structure of the NiPt centers, which was modified by the electron interaction between NiPt and CeOx and the strong metal-support interaction between NiPt-CeOx and the NGH.展开更多
Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an ...Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH3-temperature programmed desorption （TPD）, H2-temperature programmed reduction （TPR）, and X-ray photoelectron spectroscopy （XPS） were used to analyze the fresh and deactivated catalysts of Mn-CeOJTi- PILC. （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/Ti-PILC are denoted for the dopes of the catalyst of Mn-CeOJTi- PILC with Ca and K, respectively. The activities of Mn- CeOx/Ti-PILC, （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/ Ti-PILC for NH3-selective catalytic reduction （SCR） reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.展开更多
基金supported by the National Natural Science Foundation of China (No. 50976050, 51176077)the Research Fund for International Young Scientists (NO.51150110155)
文摘Titanium-pillared clays （Ti-PILCs） were obtained by different ways from TiCl4, Ti（OC3H7）4 and TiOSO4, respectively. Mn-CeOx/Ti- PILCs were then prepared and their activities of selective catalytic reduction （SCR） of NO with NH3 at low-temperature were evaluated. Mn-CeOx/Ti-PILCs were characterized by X-ray diffraction, N2 adsorption, Fourier transform infrared spectroscopy, thermal analysis, temperature-programmed desorption of ammonia and H2-temperature-programmed reduction. It was found that Ti-pillar tend to be helpful for the enlargement of surface area, pore volume, acidity and the enhancement of thermal stability for Mn-CeOx/Ti-PILCs. Mn- CeOx/Ti-PILCs catalysts were active for the SCR of NO. Among three resultant Mn-CeOx/Ti-PILCs, the catalyst from TiOSO4 showed the highest activity with 98% NO conversion at 220°C, it also exhibited good resistance to H2O and SO2 in flue gas. The catalyst from TiCl4 exhibited the lowest activity due to the unsuccessful pillaring process.
基金financially supported by the National Natural Science Foundation of China (No. 21571145)Large-scale Instrument and Equipment Sharing Foundation of Wuhan University
文摘The development of highly active noble-metal-flee catalysts for catalytic hydrolysis of ammonia borane is mandatory for its application in hydrogen storage. Herein, Co-CeOx nanoclusters have been successfully anchored on a three-dimensional nitrogen-doped graphene hydrogel （NGH） by a simple coreduction method and further used as efficient catalysts to catalytic hydrolysis of ammonia borane at room temperature. Thanks to the strong synergistic electronic effect between Co and CeOx, as well as the strong metal-support interaction between Co-CeOx and 3D NGH, the as-synthesized Co-（CeOx）0.91/NGH catalyst exhibits superior catalytic activity toward hydrolysis of ammonia borane, with the turnover frequency （TOF） value of 79.5 min 1, which is almost 13 times higher than that of Co]NGH, and higher than most of the reported noble-metal-free catalysts.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21571145）, the Creative Research Groups of Hubei Province （No. 2014CFA007）, and Large-scale Instrument and Equipment Sharing Foundation of Wuhan University.
文摘The safe and efficient storage and release of hydrogen is one of the key technological challenges for the fuel cell-based hydrogen economy. Hydrazine monohydrate has attracted considerable attention as a safe and convent chemical hydrogen-storage material. Herein, we report the facile synthesis of NiPt-CeOx nanocomposites supported by three-dimensional nitrogen-doped graphene hydrogels （NGHs） via a simple one-step co-reduction synthesis method. These catalysts were composition-dependent for hydrogen generation from an alkaline solution of hydrazine. （NisPt5）I-（CeOx）0.B/NGH exhibited the highest catalytic activity, with 100% hydrogen selectivity and turnover frequencies of 408 h^-1 at 298 K and 3,064 h^-1 at 323 K. These superior catalytic performances are attributed to the electronic structure of the NiPt centers, which was modified by the electron interaction between NiPt and CeOx and the strong metal-support interaction between NiPt-CeOx and the NGH.
文摘Mn-CeOff-l＇i-pillared clay （PILC） is an attrac- tive catalyst for selective catalytic reduction of NOx at low temperature because of its low cost. The poisoning of K and Ca on the catalyst of Mn-CeOx/Ti-PILC is an important problem because K and Ca are always in presence in flue gas. To investigate the effect of K and Ca on the physicochemical characters of the catalysts, the techniques of NH3-temperature programmed desorption （TPD）, H2-temperature programmed reduction （TPR）, and X-ray photoelectron spectroscopy （XPS） were used to analyze the fresh and deactivated catalysts of Mn-CeOJTi- PILC. （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/Ti-PILC are denoted for the dopes of the catalyst of Mn-CeOJTi- PILC with Ca and K, respectively. The activities of Mn- CeOx/Ti-PILC, （Ca）Mn-CeOx/Ti-PILC and （K）Mn-CeOx/ Ti-PILC for NH3-selective catalytic reduction （SCR） reaction at low temperature were investigated. The results showed that with the dopes of K and Ca on the catalysts, the SCR activities of the catalysts decreased greatly, and K exhibited more poisoning effect than Ca. With the dopes of K and Ca, the acidity, the redox property and chemisorbed oxygen on the surfaces of the catalysts were decreased, which resulted in a decreasing in SCR activity.
基金supported by the National Natural Science Foundation of China(0976050)Program for New Century Excellent Talents in University,China(07-0457)National Key Technology Research and Development Program of Tianjin,China(09ZCKFSH01900)~~
