A surface oxidised Fe–S catalyst for the liquid phase hydrogenation of CO2

Rapidly increasing anthropogenic carbon dioxide (CO2) emissions, coupled with irreversible climate change and depleting fossil fuel reserves, have significantly increased the drive for CO2 utilisation. Iron sulfide as a catalyst for the hydrogenation of CO2 has been discussed in the literature for decades, especially in an origin-of-life context, but little experimental evidence exists in the literature for its feasibility. Here we report the catalytic properties of pyrrhotite (Fe1−xS) for the hydrogenation of CO2 into formate. Advanced material characterisation methods in combination with computational studies have allowed us to identify surface S–Fe–O moieties as active sites for the reaction.