Unifying the 2e(-) and 4e(-) Reduction of Oxygen on Metal Surfaces

作者：Viswanathan Venkatasubramanian; Hansen Heine Anton; Rossmeisl Jan; Norskov Jens K^*

来源：Journal of Physical Chemistry Letters, 2012, 3(20): 2948-2951.

DOI：10.1021/jz301476w

Understanding trends in selectivity is of paramount importance for multi-electron electrochemical reactions. The goal of this work is to address the issue of 2e(-) versus 4e(-) reduction of oxygen on metal surfaces. Using a detailed thermodynamic analysis based on density functional theory calculations, we show that to a first approximation an activity descriptor, Delta G(OH*), the free energy of adsorbed OH*, can be used to describe trends for the 2e(-) and 4e(-) reduction of oxygen. While the weak binding of OOH* on Au(111) makes it an unsuitable catalyst for the 4e(-) reduction, this weak binding is optimal for the 2e(-) reduction to H2O2. We find quite a remarkable agreement between the predictions of the model and experimental results spanning nearly 30 years.

• 出版日期2012-10-18