Decoding the counterintuitive role of electron transfer in photothermal ammonia synthesis over Ru/CeO2 catalysts

Abstract

Electron transfer process across metal-semiconductor interface critically governs catalytic process by modulating electronic structure of catalyst, while this process becomes markedly complex in photothermal catalysis. Under light, localized surface plasmon resonance generated hot electron may transfer across interface, altering the whole electronic structure of catalyst. On the other hand, the separation of electron-hole pair is beneficial to prolong charge carrier lifetime, promoting photochemical reaction. Therefore, the impacts of electron transfer for photothermal catalytic reaction should be shaped mutually by these two effects. To our best knowledge, prolonging charge carrier lifetime was widely reported to be useful, while the influence of photo-induced electronic structure change remains elusive. Herein, we constructed well-defined Ru/ceria Schottky heterojunction model catalysts to prove how the photo-induced electronic structure change caused by electron transfer influences ammonia synthesis. We found that the intentionally inhibited electron transfer redounds to the formation of optimized electronic structure under light, improving reactant activation and spillover, finally leading to better catalytic performance. Our finding offers a new perspective for rationally designing efficient photothermal catalysts by strategically managing electron transfer dynamics.