Highly efficient hydrogenation of CO2 to heavy hydrocarbons via NaFeGa catalysts

Transforming CO2 into heavy hydrocarbons via thermal catalytic hydrogenation has garnered interest for its potential to address resource shortages and reduce atmospheric CO2. In this research, NaFeGa catalysts enriched with Ga additives were synthesized by the coprecipitation method. Various characterization techniques, including Mössbauer spectroscopy, were employed alongside reverse water-gas shift and Fischer-Tropsch synthesis experiments to elucidate the Fe-Ga interaction. This interaction effectively modulated the ratio of active sites Fe5C2 and enhanced CO species adsorption. The Ga additive's anti-hydrogenation effect limited intermediate hydrogenation, leading to increased carbon-hydrogen product yields. The catalyst underwent direct hydrogenation of CO2 under high throughput conditions (space velocity of 50,000 h−1), resulting in efficient CO2 conversion as well as remarkable heavy hydrocarbon selectivity. The catalyst demonstrated a remarkable heavy hydrocarbon space-time yield (STY) of 1460.2 g·kgcat−1·h−1, surpassing the threshold for commercial viability and offering a promising solution for large-scale production of liquid fuels from CO2. [Display omitted] •The strong iron-gallium interaction regulated the Fe5C2 active site proportion, enhancing CO intermediate adsorption.•Ga's anti-hydrogenation effect inhibits excessive hydrogenation of intermediates, promoting long-chain hydrocarbon formation.•At high throughput, the NaFeGa-30 catalyst reached a space-time yield of 1460.2 g·kg_cat-1·h-1 and remained stable for 100 h.