A Bifunctional Electrocatalyst for Oxygen Evolution and Oxygen Reduction Reactions in Water

Abstract

Oxygen reduction and water oxidation are two key processes in fuel cell applications. The oxidation of water to dioxygen is a 4 H+/4 e− process, while oxygen can be fully reduced to water by a 4 e−/4 H+ process or partially reduced by fewer electrons to reactive oxygen species such as H2O2 and O2 −. We demonstrate that a novel manganese corrole complex behaves as a bifunctional catalyst for both the electrocatalytic generation of dioxygen as well as the reduction of dioxygen in aqueous media. Furthermore, our combined kinetic, spectroscopic, and electrochemical study of manganese corroles adsorbed on different electrode materials (down to a submolecular level) reveals mechanistic details of the oxygen evolution and reduction processes.

Identifying On‐Surface Site‐Selective Chemical Conversions by Theory‐Aided NEXAFS Spectroscopy: The Case of Free‐Base Corroles on Ag(111)

“…[1][2][3][4][5][6][7] After the first synthesis of corroles more than 50 years ago, [8] rich chemistry related to their peculiarity, [9][10][11][12][13] namely the stabilization of high-valent metals tates promoting oxidation reactions, [14][15][16] has been investigated with steadily increasing effort. [14,[17][18][19][20][21][22] There are also investigations that consider well-defined interfaces formed by corrolesa dsorbed on clean substrates under ultra-high vacuum( UHV) conditions. [23][24][25][26][27][28][29] In particular, the adsorption of the prototypical free-base corrole, namely the 5,10,15-tris(pentafluorophenyl)corrole( 3H-TpFPC) (Figure 1), on Ag(111)h as recentlyb een investigated both in the multilayer [27] as well as in the (sub)monolayer regime.…”

Mono‐/Multinuclear Water Oxidation Catalysts

“…[11b, c, 68] In 2007, Gao et al studied am ononuclearm anganese complex with a corrole xanthene ligand. [71] Duringt he OER, Mn V =O was proposed as the active speciesa sar esult of CV measurements.T he mechanism of OÀOb ond formation was further studied by Gao et al in 2009. [70] For OÀO bond formation,t wo routes werep roposed:t he concerted path involves the reaction betweenM n IV -oxy and water, whereas the two-stepp ath involves coordination of the Mn ion to water,w hich can lead to OÀOb ond formation from the MnÀOH bond.…”

Silica‐Free Synthesis of Mesoporous Co3O4/CoOxPy as a Highly Active Oxygen Evolution Reaction Catalyst

“…However, the efficiency of water eletrolyzer is restricted by the slow kinetics of the oxygen evolution reaction (OER) at the electrode, which undergoes a four‐electron transfer process . Currently, the benchmark OER catalysts are mostly based on precious metals and their oxides, while the large‐scale application has been limited by their scarcity and high price . As alternatives, the development of non‐precious metal based OER catalyst with high activity and stability has attracted lots of attention .…”