Preparation Of Ni/γ-Al₂O₃Catalyst For CO₂Reforming Of Methane By Dielectric Barrier Discharge Hydrogen Plasma

Methane and carbon dioxide make a contribution of about eighty percent to the greenhouse effect. Therefore, it seems important how to effective utilize these two greenhouse gases. CO2reforming of methane (CRM), as one of the processes of hydrogen production, can apply them to produce synthesis gas with a ratio of nearly one, which can directly be used to synthesize long-chain hydrocarbons. Noble metal and nickel-based catalysts are the promising catalyst for CRM reaction. However, nobel metals are always expensive, so it is important to develop a low-cost nickel-based catalyst with high stability for the CRM reaction considering its practical application. Plasma technology has a great advantage in the preparation of supported metal catalysts. In this paper, we try to apply dielectric barrier discharge (DBD) plasma to prepare nickel based catalyst with high stability for CRM reaction.In this paper, the Ni/y-Al2O3catalyst for CRM reaction was prepared by the treatment of Ni(NO3)2/γ-Al2O3precursor with H2DBD plasma at atmospheric pressure. The results showed that discharge power obviously affected the reduction degree and catalytic performances of catalysts. Low discharge power under40W mainly resulted in the decomposition of nickel nitrate into Ni oxides. The reduction degree and catalytic activities and stability increased with the discharge power. Similar catalytic performances in CRM reaction were obtained when the power exceeded80W. The catalyst treated by H2DBD at80W exhibited better activity and stability in the CRM reaction.The Ni/γ-Al2O3catalyst treated by H2DBD at80W was compared with the catalyst prepared by conventional method. The results by XRD, CO2-TPD and N2adsorption analyses showed that the plasma-treated Ni/y-Al2O3catalyst possessed higher specific surface, enhanced nickel dispersion, more basic sites and weaker basicity. In the CRM reaction, the plasma-treated Ni/y-Al2O3catalyst performed better activity, stability and anti-carbon deposition. The increase of Ni particle sizes ascribed to the sintering at higher temperature resulted in the decrease of catalytic activities and the coke formation.