Unveiling the role of C60-supported vanadium single atoms for catalytic overall water splitting

Designing efficient bifunctional catalysts that can catalyze overall water splitting to generate hydrogen-an attractive, environmentally friendly and renewable energy carrier-is tremendously important to combat the global warming and energy crisis. Here, we report an atomistic-level understanding of the overall water splitting mechanism, 2H(2)O -> 2H(2) + O-2, mediated by C-60-supported vanadium single atoms. Detailed reaction pathways are calculated, and key intermediates with nominal chemical formulas of C60V+(H2O)(2) and C60V+O2 are characterized by infrared spectroscopy. When mediated by an isolated V+, the overall water splitting reaction stops due to geometric restrictions with end product V+(OH)(2) or V+O(H2O), whereas it can proceed to complete a catalytic cycle in the presence of the C-60-support. Our analyses reveal that the vanadium center undergoes several formal oxidation state changes resulting from the unique electron donating/accepting ability of the C60-support, acting as an electron sponge, additional to its role in facilitating the hydrogen transfer.

Automated summary

Designing efficient bifunctional catalysts for overall water splitting is important for generating hydrogen. This study provides an atomistic-level understanding of the mechanism mediated by C-60-supported vanadium single atoms, revealing the reaction pathways and key intermediates involved. The study also highlights the role of C-60 support in facilitating the reaction and its unique electron donating/accepting ability.