Study of stability of Ni/MgO/γ-Al2O3 catalyst prepared by plasma for CO2 reforming of CH4

Abstract

The Ni-based catalyst with MgO promoter was prepared by atmospheric pressure cold plasma, and it showed excellent catalytic activity and stability compared with other two correlative reference catalysts in CO2 reforming of CH4 under the conditions of 1atm, 800°C, gas hourly space velocity (GHSV)=30L/(hg), n(CH4)/n(CO2)=4/6. The XRD, TEM and XPS results proved that the good performance benefited from the combined effect of plasma reduction and MgO addition. The plasma reduction endued the catalyst with smaller primal Ni crystals by its atomic hydrogen effect at the relatively low temperature (740K) and short time (10min), and this effect can prevent the growth of Ni crystals during the reduction process; MgO promoter made for “freezing” Ni crystals by the interaction between MgO and Ni, and this interaction can not only suppress the agglomeration of Ni crystals during the reaction process, but also mitigate the decomposition of CH4 and improve the activation of CO2 as a result of the enhanced basicity of the catalyst.