Bio-inspired heterogeneous Fe4S4 single-cluster catalyst for enhanced electrochemical CO2 reduction to CH4

Electrochemical conversion of carbon dioxide promises next-level paradigm shifts in sustainability. Applications will include breakthrough solutions to global crisis threatening our civilization, including energy, food, and climate change. Here, inspired by CO dehydrogenase II from Carboxyothermus hydrogenoformans, we designed a heterogeneous Fe4S4 single-cluster catalyst Ni100-Fe4S4, achieving high performance CO2 electroreduction. Combined with the experimental data and theoretical calculation, Ni100-Fe4S4 and CO dehydrogenase have highly similar catalytic geometric centers and CO2 binding modes. By exploring the origin of catalytic activity of this biomimetic structure, we found the activation of CO2 by Ni100-Fe4S4 theoretically exceeds that of natural CO dehydrogenase. Density functional theory calculations reveal that the dehydrogenase enzyme-liked Fe-Ni active site as an electron enrichment 'electro-bridge', activating CO2 molecules efficiently and stabilizing various intermediates in multistep elementary reactions to produce CH4 in a low overpotential (0.13eV) selectively. The calculated electroreduction pathway can completely consistent with the nickel-based catalytic materials reported in the current experiments. This work demonstrates that it is efficient and feasible to design biomimetic high-performance catalytic materials by using blueprints provide by nature. Combining ideas from modern catalyst design with bio-inspired strategies will lead our catalysts beyond its current limitations.