Regulation of Metal-Support Interactions over Ni/ZrO2 Nano-Catalysts via Tuning ZrO2 Morphology for CO2 Methanation

Abstract Nickel-based catalysts are low-cost non-precious metal alternatives for CO2 methanation, yet their practical industrial applications are severely limited by the sluggish kinetic performance of low-temperature reactions and the high-temperature sintering of active nickel nanoparticles. Nanoparticles metal-support interaction (MSI) is regarded as a pivotal strategy to modulate and enhance the comprehensive catalytic performance of such catalysts. In this study, ZrO2 supports with four distinct nanoscale morphologies were fabricated successfully via hydrothermal and solvothermal synthesis routes, and a series of 10 wt.% Ni/ZrO2 catalysts were subsequently prepared through the impregnation method. The varied morphological structures of ZrO2 can effectively regulate the MSI to an optimal extent, which significantly promotes the distribution of metallic Ni active sites, and meanwhile enriches surface basic sites and nanoscale oxygen vacancies on the catalyst surface. These advantageous structural and surface modifications greatly accelerate the activation and conversion of CO2 via CO intermediate and formate reaction pathways. This study systematically clarifies the morphology-dependent regulation mechanism of MSI, providing a credible and facile strategy for the design and preparation of high-efficiency nickel-based nanocatalysts for CO2 methanation.