title: Understanding the role of gold nanoparticles in enhancing the catalytic activity of manganese oxides in water oxidation reactions.
abstract: The Earth-abundant and inexpensive manganese oxides (MnOx) have emerged as an intriguing type of catalysts for the water oxidation reaction. However, the overall turnover frequencies of MnOx catalysts are still much lower than that of nanostructured IrO2 and RuO2 catalysts. Herein, we demonstrate that doping MnOx polymorphs with gold nanoparticles (AuNPs) can result in a strong enhancement of catalytic activity for the water oxidation reaction. It is observed that, for the first time, the catalytic activity of MnOx/AuNPs catalysts correlates strongly with the initial valence of the Mn centers. By promoting the formation of Mn(3+) species, a small amount of AuNPs (<5%) in α-MnO2/AuNP catalysts significantly improved the catalytic activity up to 8.2 times in the photochemical and 6 times in the electrochemical system, compared with the activity of pure α-MnO2.
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, CT 06269 (USA).
authors.forename: Chung-Hao
authors.initials: CH
authors.lastname: Kuo
authors.forename: Weikun
authors.initials: W
authors.lastname: Li
authors.forename: Lakshitha
authors.initials: L
authors.lastname: Pahalagedara
authors.forename: Abdelhamid M
authors.initials: AM
authors.lastname: El-Sawy
authors.forename: David
authors.initials: D
authors.lastname: Kriz
authors.forename: Nina
authors.initials: N
authors.lastname: Genz
authors.forename: Curtis
authors.initials: C
authors.lastname: Guild
authors.forename: Thorsten
authors.initials: T
authors.lastname: Ressler
authors.forename: Steven L
authors.initials: SL
authors.lastname: Suib
authors.forename: Jie
authors.initials: J
authors.lastname: He
keywords: manganese oxide; metal nanoparticles; oxygen evolution reaction; transition-metal oxides; water oxidation