Hydrogen production from methane decomposition over Ni/CeO 2 catalysts

Abstract

The catalytic behavior of Ni/CeO 2 catalysts was investigated for methane decomposition at 773 K. Ni/CeO 2 catalysts prepared by impregnation and deposition–precipitation methods showed much higher hydrogen formation rates than that of Ni/CeO 2 catalyst prepared by coprecipitation method, which exhibited relatively higher CO formation rate. CH 4-TPSR measurements confirmed that CO formation is inevitable during methane decomposition, since the lattice oxygen of ceria could react with the deposited carbons. TEM observations further indicated that the morphologies as well as the reactivities of the deposited carbons are strongly dependent on the interaction degrees between Ni and ceria, which in turn explains the differences in the catalytic activity of the Ni/CeO 2 catalysts for methane decomposition. The Ni/CeO 2 catalyst prepared by coprecipitation method exhibited rather strong metal–support interaction probably through the formation of Ni–O–Ce solid solution, resulting in much lower hydrogen formation rate and relatively higher CO production.