A comparative study of the effect of metal-support interaction on catalytic CO2 methanation over Ni/CexZr1-xO2 catalysts under thermal and plasma conditions

Abstract

Metal-support interaction (MSI) is a well-established strategy for tuning catalytic activity in thermal catalysis, yet its role in nonthermal plasma catalytic CO2 methanation remains insufficiently explored. In this study, the Ni/CexZr1-xO2 catalysts were synthesized using CexZr1-xO2 supports calcined at different temperatures to systematically modulate MSI. A volcano-shaped correlation was observed between catalytic activity and support calcination temperature in both thermal and plasma systems. The CexZr1-xO2 support calcined at 600 °C having a moderate particle size, demonstrated optimum MSI (i.e., promoting the facile formation of oxygen vacancies and stable interfacial anchoring of Ni particles) and thus the comparatively best catalytic performance under both conditions. Under the tested conditions, thermal CO2 methanation exhibited superior activity compared to plasma-assisted reactions, e.g., over the NCZ-600 catalyst achieved an 83% CH4 yield at 350 °C versus 11.3% at 7.0 kV. These results underscore the critical role of MSI in governing CO₂ methanation across distinct catalytic environments and highlight its potential as a unifying design principle for both thermal and plasma catalysis.