CO₂ fixation into methanol at Cu/ZrO₂ interface from first principles kinetic Monte Carlo

The efficient fixation/utilization of CO₂ has been pursued by chemists for decades. In this work, the catalytic kinetics of CO₂ fixation to methanol over a binary catalyst Cu/ZrO₂ is investigated by first principles kinetic Monte Carlo simulation. A Cu/ZrO₂ interface model is first established and the reaction network of CO₂ hydrogenation is explored. In the Cu/ZrO₂ system two reaction channels to methanol are identified (i) a reverse water-gas shift reaction via CO₂ decomposition to CO and (ii) the well-regarded mechanism via a formate intermediate. The theoretical selectivity is determined to be 85% for methanol and 15% for CO. The removal of the oxidative species is kinetically slow. As a result, 87% of the interface sites are covered by these oxidative species, which oxidize the interface Cu. We show that the binding strength of O atom at the interface is a critical parameter determining the activity and selectivity of the catalyst.