Theory-guided design of hydrogen-bonded cobaltoporphyrin frameworks for highly selective electrochemical H<sub>2</sub>O<sub>2</sub> production in acid.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35581214.
- Also identified by DOI 10.1038/s41467-022-30523-0 and PMC identifier 9114359.
- 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 pursuit of selective two-electron oxygen reduction reaction to H<sub>2</sub>O<sub>2</sub> in acids is demanding and largely hampered by the lack of efficient non-precious-metal-based electrocatalysts. Metal macrocycles hold promise, but have been relatively underexplored. Efforts are called for to promote their inherent catalytic activities and/or increase the surface exposure of active sites. In this contribution, we perform the high-throughput computational screening of thirty-two different metalloporphyrins by comparing their adsorption free energies towards key reaction intermediates. Cobalt porphyrin is revealed to be the optimal candidate with a theoretical overpotential as small as 40 mV. Guided by the computational predictions, we prepare hydrogen-bonded cobaltoporphyrin frameworks in order to promote the solution accessibility of catalytically active sites for H<sub>2</sub>O<sub>2</sub> production in acids. The product features an onset potential at ~0.68 V, H<sub>2</sub>O<sub>2</sub> selectivity of >90%, turnover frequency of 10.9 s<sup>-1</sup> at 0.55 V and stability of ~30 h, the combination of which clearly renders it stand out from existing competitors for this challenging reaction.