Template-free synthesis of wormhole-like mesoporous Ni–Al composite oxides and catalytic application for steam reforming of benzene

摘要

Mesoporous Ni–Al composite oxides (Ni x Al, x = 0.05, 0.1, 0.125, 0.25, 0.5) with different Ni/Al molar ratio have been successfully prepared by partial hydrolysis of aqueous solution of Al(NO3)3 and Ni(NO3)2 with (NH4)2CO3 solution without templates or organic surfactants. The samples exhibit a wormhole-like mesoporous structures with large specific surface areas of 105–213 m2/g and narrow pore size distributions. With increasing Ni/Al molar ratio, BET surface areas decrease, while BJH pore diameters increase. Nickel species are highly dispersed in the alumina frameworks through the formation of Ni–Al composite oxides. The comparative investigation for the reforming of benzene over the prepared Ni0.1Al catalyst and the counterpart obtained by templating method reveals that prepared Ni0.1Al catalyst shows high stability and coke resistance ability because of the better mass transfer properties of the wormhole-like mesostructure.