Boosting electrochemical oxygen reduction to hydrogen peroxide coupled with organic oxidation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39030230.
- Also identified by DOI 10.1038/s41467-024-50446-2 and PMC identifier 11271547.
- 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 electrochemical oxygen reduction reaction (ORR) to produce hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) is appealing due to its sustainability. However, its efficiency is compromised by the competing 4e<sup>-</sup> ORR pathway. In this work, we report a hierarchical carbon nanosheet array electrode with a single-atom Ni catalyst synthesized using organic molecule-intercalated layered double hydroxides as precursors. The electrode exhibits excellent 2e<sup>-</sup> ORR performance under alkaline conditions and achieves H<sub>2</sub>O<sub>2</sub> yield rates of 0.73 mol g<sub>cat</sub><sup>-1</sup> h<sup>-1</sup> in the H-cell and 5.48 mol g<sub>cat</sub><sup>-1</sup> h<sup>-1</sup> in the flow cell, outperforming most reported catalysts. The experimental results show that the Ni atoms selectively adsorb O<sub>2</sub>, while carbon nanosheets generate reactive hydrogen species, synergistically enhancing H<sub>2</sub>O<sub>2</sub> production. Furthermore, a coupling reaction system integrating the 2e<sup>-</sup> ORR with ethylene glycol oxidation significantly enhances H<sub>2</sub>O<sub>2</sub> yield rate to 7.30 mol g<sub>cat</sub><sup>-1</sup> h<sup>-1</sup> while producing valuable glycolic acid. Moreover, we convert alkaline electrolyte containing H<sub>2</sub>O<sub>2</sub> directly into the downstream product sodium perborate to reduce the separation cost further. Techno-economic analysis validates the economic viability of this system.