Defective Sn-Zn perovskites through bio-directed routes for modulating CO2RR

Sn and Zn oxides can catalyze electrochemical CO2 reduction reactions (CO2RR) to produce useful chemicals. Herein, we report on perovskite-type tin-zinc oxides (TZO) synthesized by a biomineralization approach under benign aqueous conditions. The resulting TZO catalysts are disordered and possess a high quantity of defects, which serve as highly reactive active sites in CO2RR. Selectively toward formate or CO is tunable toward the relative amounts of Sn and Zn and their associated O defects. In-situ X-ray absorption spectroscopy measurements reveal electronic and structural transformations consistent with oxygen vacancy formation at Sn-O-Zn bridges as a function of cathodic potential that strongly correlates to CO2RR selectivity. Density functional theory (DFT) calculations demonstrate that introducing an oxygen vacancy in TZO influences drastically influences formate/CO selectivity, consistent with our in-situ XAS findings and catalytic performance. Overall, these findings demonstrate the potential of biomineralization to fabricate perovskite-type metal oxides for energy conversion reactions.

Automated summary

This study synthesized perovskite-type tin-zinc oxide catalysts using a biomineralization method and found that these catalysts have highly reactive active sites and tunable CO2RR selectivity. In-situ X-ray absorption spectroscopy measurements and density functional theory calculations revealed the impact of oxygen vacancies on the catalytic performance.