The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compare...The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate support surface, resulting in formation of persion of the active phase and significant aqueous solution could enhance interaction with very small NiO particle size （〈5 nm）, high discatalytic activity. Particle size of Ni^0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni^0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at iow temperature of 55 ℃.展开更多
Methane catalytic decomposition (MCD) over Ni/MCM-41 catalysts was tested in a microreactor to simultaneously produce hydrogen and carbon nanotubes (CNTs). The methane conversion reached 30% to 47% at a moderate tempe...Methane catalytic decomposition (MCD) over Ni/MCM-41 catalysts was tested in a microreactor to simultaneously produce hydrogen and carbon nanotubes (CNTs). The methane conversion reached 30% to 47% at a moderate temperature range from 400°C to 600°C and the catalytic activity of the catalysts remains stable during 500 min steam on time. CNTs were chiefly formed through tip-growth mode, due to the weak interaction between the metallic Ni and the support. Most of the Ni particles are located on the tip of the produced CNTs, which avoids rapid deactivation of the catalyst resulted from carbon encapsulation. Large Ni particles usually lead to the formation of CNTs with big diameter. During the reaction, the shape of Ni particles changed from pseudo-sphere to diamond-like. All the CNTs consist of multiple layer walls and are curved in certain degree.展开更多
基金V. ACKNOWLEDGMENTS This work was supported by the National High-Tech Research and Development 863 Program of China （No.2012AA101806）, the National Natural Science Foundation of China （No.21306195 and No.51276183）, and the National Key Basic Research Program 973 Project from Ministry of Science and Technology of China （No.2012CB215304）.
文摘The activities of nickel supported on MCM-41 catalysts, prepared by co-impregnation with polyols （ethylene glycol, glycerol, xylitol, sorbitol and glucose）, were investigated by hydrogenation of naphthalene. Compared with the conventional wetness impregnation, addition of moderate polyols into the metal nitrate support surface, resulting in formation of persion of the active phase and significant aqueous solution could enhance interaction with very small NiO particle size （〈5 nm）, high discatalytic activity. Particle size of Ni^0 decreased from 36.1 nm to below 5 nm; meanwhile the complete hydrogenation of naphthalene was dependent on the Ni^0 particle size. The hydrogenation activities of the catalysts prepared by co-impregnation with polyols were very high with 100% conversion even at iow temperature of 55 ℃.
文摘Methane catalytic decomposition (MCD) over Ni/MCM-41 catalysts was tested in a microreactor to simultaneously produce hydrogen and carbon nanotubes (CNTs). The methane conversion reached 30% to 47% at a moderate temperature range from 400°C to 600°C and the catalytic activity of the catalysts remains stable during 500 min steam on time. CNTs were chiefly formed through tip-growth mode, due to the weak interaction between the metallic Ni and the support. Most of the Ni particles are located on the tip of the produced CNTs, which avoids rapid deactivation of the catalyst resulted from carbon encapsulation. Large Ni particles usually lead to the formation of CNTs with big diameter. During the reaction, the shape of Ni particles changed from pseudo-sphere to diamond-like. All the CNTs consist of multiple layer walls and are curved in certain degree.
