Hydrogen production by auto-thermal reforming of ethanol over Ni-Ti-Zr metal oxide catalysts

A series of Ni5TixZr5 − xO15 (x = 0, 1, 2.5, 4, and 5) catalysts was prepared by a one-step sol-gel method for use in hydrogen production by auto-thermal reforming of ethanol. The effect of the Ti:Zr ratio on the crystalline structure, electronic property, and catalytic performance of Ni5TixZr5 − xO15 was investigated. The coexistence of titanium and zirconium favorably served to form metallic nickel (Ni0) species, and the reducibility of nickel oxide species was closely related to the catalytic performance of Ni5TixZr5 − xO15 catalysts. The hydrogen selectivity over Ni5TixZr5 − xO15 catalysts showed a volcano-shaped curve with respect to titanium substitution. Along with the reducibility, the water-activation ability of ZrO2 was an important factor affecting the catalytic performance. Among the catalysts tested, Ni5Ti1Zr4O15 showed the best catalytic performance.