Phosphate-modified Al2O3–ZrO2 supported Ni catalysts for efficient selective methanation of CO in H2-rich reformate gas

Abstract

CO selective methanation can remove the CO in H2-rich reformate gas to prevent the poisoning of Pt anode electrode in proton exchange membrane fuel cell. However, the methanation of CO2 in H2-rich gas consumes a lot of hydrogen, which greatly reduces the energy efficiency. In order to inhibit CO2 methanation, mesostructured Al2O3–ZrO2 was modified by different amounts of phosphate, and then was as Ni support. The structures and surface properties of Ni/Al2O3–ZrO2 catalyst modified by phosphate were studied to reveal the effect of phosphate-modification on CO conversion and selectivity for CO methanation. It was found that the phosphate-modification inhibited the adsorption of CO2, which increased the selective for CO methanation. But the modification with excess phosphate lessened active sites of Ni and weakened the adsorption of H2 and CO, which decreased the activity of CO methanation.