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

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 CeZrOx/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. Low-temperature CO2 methanation processes have potential for improved energy efficiency due to high equilibrium conversion but are generally limited by poor catalyst activity. Here the authors report an inverse CeZrOx/Ni catalyst that realizes high low-temperature (200 °C) methanation activity at ambient pressure.