Transition Metals Modified Ni−M (M=Fe, Co, Cr and Mn) Catalysts Supported on Al2O3−ZrO2 for Low‐Temperature CO2 Methanation

Abstract

AbstractAlthough considerable efforts have been made in transforming carbon dioxide into high value‐added products, it still remains a big challenge to convert CO2 to CH4 directly at low temperature. Here, we report transition metals (including Fe, Co, Cr and Mn) modified Ni catalysts supported on Al2O3−ZrO2 via a single‐step sol‐gel method for low temperature CO2 methanation. Specially, incorporation of Mn metal into the Ni/Al2O3−ZrO2 catalyst was the most beneficial to the reduction and dispersion of NiO particles on the surface of Al2O3−ZrO2 composite support in comparison to other transition metals such as Fe, Co and Cr, which promoted the formation of active metallic Ni sites. Furthermore, the addition of Mn promoter facilitated the formation of surface oxygen vacancies, which combined with more metallic Ni active sites, thus improving the low‐temperature CO2 methanation performance significantly. An optimized Ni−Mn/Al2O3−ZrO2‐1 catalyst exhibited a superior CO2 conversion of 78 % with CH4 selectivity almost 100 % at a lower temperature of 300 °C without any deactivation in the long term 100 h reaction, which presented a potential industrial application for CO2 methanation.