Engineering MOx/Ni inverse catalysts for low-temperature CO2 activation with high methane yields

Abstract

Low-temperature methanation allows the near-equilibrium conversion of CO₂ to methane at atmospheric pressure, promising remarkable energy efficiency and economic interests. However, it remains challenging for the efficient catalytic activation of CO₂ at low temperature owing to the kinetic limitations of hydrogenation intermediates. Here we report that Ni-based inverse catalysts composed of oxide nano-islands loaded on metallic Ni support show significant activity advantages over traditional Ni/oxide with the same composition. The optimized CeZrO_x/Ni catalyst realizes ~90% CO₂ conversion and >99% CH₄ selectivity at 200 °C and atmospheric pressure; it also exhibits excellent long-term stability and overheating/start–stop cyclic operation stability. Mechanistic studies show that the inverse interface effectively modulates H₂ and CO₂ coverage and alters the configuration of adsorbed oxygenates, which benefits the hydrogenation of surface intermediates. Energy and economic analyses demonstrate that the low-temperature CO₂ methanation process powered by inverse catalysts potentially reduces both capital investment and methane production costs.