Catalytic behavior of Ni/ZrxTi1−xO2 and the effect of SiO2 doping in oxidative steam reforming of n-butane

Catalytic behaviors of TiO2-, Zr0.5Ti0.5O2-, and ZrO2-supported Ni catalysts were investigated for oxidative steam reforming of n-C4H10 at 723 K. The composite oxide support, Zr0.5Ti0.5O2, shows high specific surface area (136 m2/g), leading to fine Ni particles. Thus, the Ni/Zr0.5Ti0.5O2 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 SiO2 additive was studied. Large amounts of SiO2 additive (5 or 10 mol%) decrease initial activity; at 10 mol%, degradation is also induced by oxidation of Ni0. However, small amounts of SiO2 additive (1.5 mol%) effectively retard coking without lowering initial activity. The resultant Ni/Zr0.5Ti0.5O2–SiO2 (1.5 mol%) catalyst exhibits high and stable activity without coking.