A Novel Reduction Method for Ni/γ-Al2O3 Catalyst by a High Frequency Cold Plasma Jet at Atmospheric Pressure

Abstract

Abstract The Ni/γ-Al2O3 catalyst was reduced by a high frequency cold plasma jet at atmospheric pressure. The performance of the catalyst for carbon dioxide reforming of methane was investigated. The process of catalyst reduction with plasma was quick and simple and was completed in only 10 min, giving activity and selectivity higher than those of the catalyst prepared by the conventional method. At the CH4/CO2 molar ratio of 4/6 and the reaction temperature of 850°C, the methane conversion and CO2 conversion reached up to 95.77% and 75.65%, respectively, and a hydrogen selectivity of 100% and a CO selectivity of 94.79% were obtained over the novel catalyst reduced by plasma. The novel catalyst exhibited good stability during a reaction test for 36 h. XRD characterization showed that only a metallic nickel phase and γ-alumina existed in the catalyst reduced by plasma, and the NiAl2O4 phase and other nickel oxides were not detected. The nickel particle size of the catalyst was smaller than that of the conventional catalyst. An enhanced dispersion was achieved with the plasma reduction.