A high-performance oxygen evolution catalyst in neutral-pH for sunlight-driven CO<sub>2</sub> reduction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31501446.
- Also identified by DOI 10.1038/s41467-019-12009-8 and PMC identifier 6733866.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The efficiency of sunlight-driven reduction of carbon dioxide (CO<sub>2</sub>), a process mimicking the photosynthesis in nature that integrates the light harvester and electrolysis cell to convert CO<sub>2</sub> into valuable chemicals, is greatly limited by the sluggish kinetics of oxygen evolution in pH-neutral conditions. Current non-noble metal oxide catalysts developed to drive oxygen evolution in alkaline solution have poor performance in neutral solutions. Here we report a highly active and stable oxygen evolution catalyst in neutral pH, Brownmillerite Sr<sub>2</sub>GaCoO<sub>5</sub>, with the specific activity about one order of magnitude higher than that of widely used iridium oxide catalyst. Using Sr<sub>2</sub>GaCoO<sub>5</sub> to catalyze oxygen evolution, the integrated CO<sub>2</sub> reduction achieves the average solar-to-CO efficiency of 13.9% with no appreciable performance degradation in 19 h of operation. Our results not only set a record for the efficiency in sunlight-driven CO<sub>2</sub> reduction, but open new opportunities towards the realization of practical CO<sub>2</sub> reduction systems.