Thermo‐catalytic conversion of greenhouse gases (CO 2 and CH 4 ) to CO‐rich hydrogen by CeO 2 modified calcium iron oxide supported nickel catalyst

SUMMARY In this study, the thermo‐catalytic conversion of two principal greenhouse gases (methane and carbon dioxide) to carbon monoxide (CO)‐rich hydrogen (H 2 ) is investigated over cerium oxide (CeO 2 ) promoted calcium ferrite supported nickel (Ni/CaFe 2 O 4 ) catalyst. The CeO 2 promoted Ni/CaFe 2 O 4 catalyst was prepared using wet‐impregnation technique. To ascertain the physicochemical properties, the as‐prepared catalyst was characterized using various instrument techniques. The characterization of the catalysts reveals that CeO 2 ‐Ni/CaFe 2 O 4 possesses suitable physicochemical properties for the conversion of methane (CH 4 ) and carbon dioxide (CO 2 ) to CO‐rich H 2 . The thermo‐catalytic reaction revealed that the CeO 2 promoted Ni/CaFe 2 O 4 catalyst displayed a higher CH 4 and CO 2 conversions of 90.04% and 91.2%, respectively, at a temperature of 1073 K compared to the unpromoted catalyst. The highest H 2 and CO yields of 78% and 76%, respectively, were obtained over the CeO 2 ‐Ni/CaFe 2 O 4 at 1073 K and CH 4 /CO 2 ratio of 1. The CeO 2 promoted Ni/CaFe 2 O 4 catalyst remained stable throughout the 30 hours time on stream (TOS) while that of the unpromoted Ni/CaFe 2 O 4 catalyst sharply decreased after 22 hours TOS. The characterization of the used catalysts confirms the evidence of carbon depositions on the unpromoted Ni/CaFe 2 O 4 which is solely responsible for its deactivation. Whereas, there was a slightly gasifiable carbon deposited on the CeO 2 promoted Ni/CaFe 2 O 4 catalyst which could be ascribed to the interaction effect of the CeO 2 promoter on the Ni/CaFe 2 O 4 catalyst.