Thermally stable Ni foam-supported inverse CeAlO_x/Ni ensemble as an active structured catalyst for CO₂ hydrogenation...

Nickel is the most widely used inexpensive active metal center of the heterogeneous catalysts for CO₂ hydrogenation to methane. However, Ni-based catalysts suffer from severe deactivation in CO₂ methanation reaction due to the irreversible sintering and coke deposition caused by the inevitable localized hotspots generated during the vigorously exothermic reaction. Herein, we demonstrate the inverse CeAlO_x/Ni composite constructed on the Ni-foam structure support realizes remarkable CO₂ methanation catalytic activity and stability in a wide operation temperature range from 240 to 600 °C. Significantly, CeAlO_x/Ni/Ni-foam catalyst maintains its initial activity after seven drastic heating-cooling cycles from RT to 240 to 600 °C. Meanwhile, the structure catalyst also shows water resistance and long-term stability under reaction condition. The promising thermal stability and water-resistance of CeAlO_x/Ni/Ni-foam originate from the excellent heat and mass transport efficiency which eliminates local hotspots and the formation of Ni-foam stabilized CeAlO_x/Ni inverse composites which effectively anchored the active species and prevents carbon deposition from CH₄ decomposition.