Catalytic Effects and Characteristics of Ni-based CatalystsSupported on TiO2-SiO2 Xerogel

[摘要] The catalytic activities of nickel-based catalysts were estimated for oxidizing acetaldehyde of VOCs exhausted from industrial facilities. The catalysts were prepared by sol-gel methods of SiO₂ and SiO₂-TiO₂ as a xerogel followed by impregnating Al₂O₃ powder with the nickel nitrate precursor. The crystalline structure and catalytic properties for the catalysts were investigated by use of BET surface area, X-ray diffraction (XRD), Xray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR) techniques. These results show that nickel oxide is transformed to NiAl₂O₄ spinel structure at the calcination temperature of 400 ∑C in response to the steps with after- and co-impregnation of Al2O3 powder in sol-gel process. The NiAl₂O₄ could suppress the oxidation reaction of acetaldehyde by catalysts. The NiO is better dispersed on SiO₂-TiO₂/Al₂O₃ support than SiO₂/Al₂O₃ and SiO₂-TiO₂-Al₂O₃ supports. From the testing results of catalytic activities for oxidation of acetaldehyde, Catalysts showed a big difference in conversion efficiencies with the way of the preparation of catalysts and the loading weight of nickel. The catalyst of 8 wt.% Ni/TiO₂-SiO₂/Al₂O₃ showed the best conversion efficiency on acetaldehyde oxidation with 100% conversion efficiency at 350 ∑C.

[学科分类] 化学（综合）

[关键词] Nickel (Ni);Oxidation catalyst;Sol-gel;TiO2-SiO2 xerogel;Acetaldehyde