Catalytic behavior of Ni/Zr xTi 1−xO 2 and the effect of SiO 2 doping in oxidative steam reforming of n-butane

Abstract

Catalytic behaviors of TiO 2-, Zr 0.5Ti 0.5O 2-, and ZrO 2-supported Ni catalysts were investigated for oxidative steam reforming of n-C 4H 10 at 723 K. The composite oxide support, Zr 0.5Ti 0.5O 2, shows high specific surface area (136 m 2/g), leading to fine Ni particles. Thus, the Ni/Zr 0.5Ti 0.5O 2 catalyst exhibits higher and more stable activity than that exhibited by other catalysts. However, relatively large amounts of coke are deposited on the catalyst during reaction. Thus, to retard carbon deposition, the influence of SiO 2 additive was studied. Large amounts of SiO 2 additive (5 or 10 mol%) decrease initial activity; at 10 mol%, degradation is also induced by oxidation of Ni 0. However, small amounts of SiO 2 additive (1.5 mol%) effectively retard coking without lowering initial activity. The resultant Ni/Zr 0.5Ti 0.5O 2–SiO 2 (1.5 mol%) catalyst exhibits high and stable activity without coking.