Highly efficient electron-enriched Y2O3–x-Ni interfaces boosting low-temperature CO2 methanation

CO 2 methanation technology has shown great application prospects in carbon neutrality and hydrogen storage due to its extremely high energy efficiency and potential economic benefits. It is highly desirable but challenging to design novel catalyst and achieve efficient and stable CO 2 methanation under mild conditions. Herein, we developed a highly active electron-enriched Y 2 O 3 /Ni catalyst, achieving a stable operation with ~80.1% CO 2 conversion and ~100% CH 4 selectivity for 400 h at 0.1 MPa and 220 °C, which was a 100 °C lower than the conventional supported Ni-based catalysts. Structural characterizations confirmed that the Y 2 O 3 /Ni catalyst maintained dynamic redox changes and formed electron-enriched Y 2 O 3– x -Ni interfaces under reaction conditions. Mechanism studies proved that the Y 2 O 3– x -Ni interfaces obviously lowered the energy barrier of *HCO dissociation, and shifted the rate-determining step from *HCO dissociation to *CO hydrogenation. Furthermore, profited by the moderate CO x adsorption ability and higher H 2 coverage at the Y 2 O 3– x -Ni interfaces, the *CO hydrogenation reaction was kinetically promoted. The above factors accounted for the excellent low-temperature CO 2 methanation activity of the Y 2 O 3 /Ni catalyst.