Lattice strained Na-ZnFe2O4 catalyst boosting CO2 hydrogenation to long-chain olefins

Abstract

Thermo-catalytic hydrogenation of CO₂ to fuels and chemicals is an effective way for the utilization of CO₂, yet it faces significant challenges due to the low CO₂ conversion and product selectivity. Here, we report a lattice-strained FeZnNa catalyst synthesized via mechanochemical method (FeZnNa-G), showing the high selectivity of C₄₊ long-chain olefins (C₄₊⁼ ) of 64.9% and C₂₊⁼ of 77.5% at a high CO₂ conversion of 47.7%. We found that the lattice-contracted FeZnNa-G catalyst forms Na-enriched ZnO nano-islands on the surface after activation and a Na-ZnO/Fe₅C₂ structure with the presence of 97% Fe₅C₂, facilitating the formation of HCOO^* intermediate and enhancing CO₂ activation. A high C₄₊⁼ space-time yield (STY) of 474.9 mg•g_cat^-1•h^-1 and an extremely low CO selectivity of ~9.1% exhibited the dual-high performance significantly surpassing the previous reports. This use of lattice strained catalyst offers a new strategy for the efficient conversion of CO₂ into high-value olefins, and paves the way for the potential industry application in future.