Decoration of the layered manganese oxide birnessite with Mn(ii/iii) gives a new water oxidation catalyst with fifty-fold turnover number enhancement

Abstract

The role of the manganese average oxidation state (AOS) in water oxidation catalysis by birnessite was investigated. Low AOS samples were most active, generating O₂ immediately. Samples with a relatively high AOS showed an initial induction period and decreased turnover. Mn(II- and III)-enriched samples gave a 10–50 fold enhancement in turnover number.