An Operando Investigation of (Ni-Fe-Co-Ce)Ox System as Highly Efficient Electrocatalyst for Oxygen Evolution Reaction
An Operando Investigation of (Ni-Fe-Co-Ce)Ox System as Highly Efficient Electrocatalyst for Oxygen Evolution Reaction
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DOI：
10.1021/acscatal.6b03126
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发表时间：
2017-02-01
期刊：
影响因子：
12.9
通讯作者：
Yano, Junko
中科院分区：
文献类型：
--
作者：
Favaro, Marco;Drisdell, Walter S.;Yano, Junko
析氧反应（OER）是金属电解和氯碱工艺等工业过程的关键组成部分。它还在可再生能源领域的发展中发挥着核心作用，通过提供产生燃料所需的质子和电子，如H-2或从CO2中还原的碳氢化合物。为了改善这些过程，有必要扩大在低过电位下的催化活性物种的基本理解，这将进一步发展具有高活性和耐久性的电催化剂。在这种情况下，在现实的工作状态（即，在操作条件下）是至关重要的。在这里，我们研究了一个高活性的五元过渡金属氧化物为基础的OER电催化剂通过operando常压X射线光电子能谱和X射线吸收光谱在固/液界面进行。我们观察到，催化剂经历了一个明确的化学结构演变的功能与Ni，Fe，和Co的羟基氧化物包括活性催化物种的施加电位。虽然CeO 2在催化条件下是氧化还原非活性的，但其对过渡金属氧化还原过程的影响在低过电位下提高了催化活性，为电催化剂的优化和高性能材料的定制引入了重要的设计原则。
The oxygen evolution reaction (OER) is a critical component of industrial processes such as electrowinning of metals and the chlor-alkali process. It also plays a central role in the development of a renewable energy field for generation a solar fuels by providing both the protons and electrons needed to generate fuels such as H-2 or reduced hydrocarbons from CO2. To improve these processes, it is necessary to expand the fundamental understanding of catalytically active species at low overpotential, which will further the development of electrocatalysts with high activity and durability. In this context, performing experimental investigations of the electrocatalysts under realistic working regimes (i.e., under operando conditions) is of crucial importance. Here, we study a highly active quinary transition-metal-oxide-based OER electrocatalyst by means of operando ambient-pressure X-ray photoelectron spectroscopy and X-ray absorption spectroscopy performed at the solid/liquid interface. We observe that the catalyst undergoes a clear chemical-structural evolution as a function of the applied potential with Ni, Fe, and Co oxyhydroxides comprising the active catalytic species. While CeO2 is redox inactive under catalytic conditions, its influence on the redox processes of the transition metals boosts the catalytic activity at low overpotentials, introducing an important design principle for the optimization of electrocatalysts and tailoring of high-performance materials.