Identifying the key structural features of Ni-based catalysts for the CO2 methanation reaction

Identifying the parameters influencing the selectivity of products is prominently significant for fabricating efficient catalysts. However, little progress has been made in describing the regulation rule of CH4 selectivity toward the CO2 methanation reaction, which is considered a vital process for CO2 emission and conversion. Herein, we disclosed the integral role of the electronegativity of M atoms in Ni-MOx supported catalysts to producing CH4 molecules, which the satisfactory catalytic performance stemmed from the regulated ability to capture CO2 molecules and CO intermediates. More importantly, alongside the extensively studied descriptor of particle size, we uncovered a strong correlation between the electronegativity of M atom and CH4 selectivity, in which the CO/CO2 adsorption capacity upon the Ni/NiOx/MOx interfaces exhibited a volcanic trend based on the electronegativity of M atoms in MOx supports. The screened Ni-Y2O3 composite catalysts demonstrated excellent CO2 methanation performance, suggesting the powerful practicability of the electronegativity of M atoms in MOx supports as a descriptor. These findings not only shed fundamental insight into the reaction pathway but also paved the way for the rational design of Ni-based catalysts based on the simple descriptor of electronegativity.