Single-atom Cu1/ZrO2 coupled with SAPO-34 enhances CO2 hydrogenation to light olefins

Abstract

CO₂ reduction to light olefins is an important pathway toward carbon neutrality, but it is hindered by low thermodynamic conversion and the inherent trade-off between activity and selectivity. To address this challenge, a bifunctional catalyst consisting of Cu single atoms anchored on ZrO₂ and SAPO-34 (Cu₁/ZrO₂-SAPO-34) was developed. This catalyst achieves 84.3% light olefin selectivity and 15.0% CO₂ conversion, with stable performance maintained over 100 hours. In this catalyst, Cu single atoms, ZrO₂, and SAPO-34 exhibit clear division of labor and synergy, responsible for CO₂ activation, active site stabilization, and olefin selectivity control, respectively. Mechanistic investigations using in situ DRIFTS and DFT calculations demonstrate that the interaction between Cu single atoms and ZrO₂ facilitates the further hydrogenation of formate intermediates to methoxy species, while reducing the energy barrier for methoxy hydrogenation to methanol, thus ensuring high light olefin selectivity in subsequent conversion over SAPO-34. This work provides new insights for CO₂ conversion and the design and application of single-atom catalysts in tandem catalytic reactions.