Promotion effects of CeO2 and Pd on Ni/γ-Al2O3 catalyst

The influence of the addition of n-type semiconductor oxide CeO2 and noble metal Pd to Ni/gamma-Al2O3 catalyst on carbon deposition by CH4 and carbon elimination by CO2 was studied by using a pulse microreaction as well as BET, TPR, CO2-TPSR and hydrogen chemisorption techniques. It was found that, the addition of n-type semiconductor CeO2 to Ni/gamma-Al2O3 catalyst could decrease carbon deposition activity of CH4 and increase carbon elimination ability of CO2; the addition of noble metal Pd could further alter the interaction between support Al2O3, promoter CeO2 and active phase Ni, as a result, the performance of resistance to carbon deposition of Ni/gamma-Al2O3 catalyst was improved. At the same time, a new explanation for the above promoting effect was put forward by the models of carbon deposition by CH4 and carbon elimination by CO2 on the Ni-Ce-Pd/gamma-Al2O3 catalyst.