Effect of Ca doping on the catalytic performance of CuO–CeO2 catalysts for methane combustion

Methane catalytic combustion was carried out over a series of Ca doped Ce0.9 − xCu0.1CaxOδ (0 < x ≤ 0.3) catalysts prepared by the citric acid complexation–combustion method. The catalyst with x = 0.05 showed the optimum activity, with T50 = 478 °C, 60 °C lower than that of Ca undoped catalyst. The Ca doping promoted the formation of oxygen vacancies of the catalyst. With the increase in Ca amount, more carbonate species were formed on the catalyst surfaces. The carbonate species produced on the catalysts after long-term reaction, were proposed to be responsible for the activity loss of the catalysts.