CO2 reforming of methane on Ni/γ-Al2O3 catalyst prepared by dielectric barrier discharge hydrogen plasma

Abstract

Ni/γ-Al2O3 catalyst was prepared by direct treatment of Ni(NO3)2/γ-Al2O3 precursor with dielectric barrier discharge (DBD) hydrogen plasma at different input powers, characterized by XRD, H2-TPR, CO2-TPD, N2 adsorption and TEM, respectively, and used as the catalyst for CO2 reforming of methane (CRM). The results showed that the input power obviously affected the reduction degree and catalytic performances of catalysts. Low input power under 40 W mainly resulted in the decomposition of nickel nitrate into Ni oxides. The reduction degree, catalytic activity and stability increase with the input power. Similar catalytic performances in CRM reaction can be obtained when the power exceeds 80 W. Compared with the Ni/Al2O3 catalyst prepared by traditional method, Ni/γ-Al2O3 samples prepared by H2 DBD plasma exhibit better activities, stability and anti-carbon deposit performances. It is mainly ascribed to smaller Ni particle size, more basic sites and weaker basicity. The increase of Ni particle sizes due to the sintering at high temperature results in the decrease of catalytic activities and coke formation.