Preferential Methanation of CO using Halogen‐Doped (F, Cl, Br) Ceria‐Supported Nickel Catalysts

Abstract Halogen‐doped Ni(F)/CeO 2 , Ni(Cl)/CeO 2 , and Ni(Br)/CeO 2 catalysts were prepared by treating halogen‐free Ni/CeO 2 with aqueous solutions of NH 4 F, NH 4 Cl, and NH 4 Br, respectively. It was demonstrated that the halogen dopants had distinct effects on the catalyst properties for the CO preferential methanation using realistic reformate gas: fluorine did not change catalytic activity, chlorine inhibited CO 2 methanation activity and provided high selectivity towards CO methanation, and bromine completely inhibited both the CO and CO 2 methanation activity.