Measurements of Oxygen Electroadsorption Energies and Oxygen Evolution Reaction on RuO2(110): A Discussion of the Sabatier Principle and Its Role in Electrocatalysis
Measurements of Oxygen Electroadsorption Energies and Oxygen Evolution Reaction on RuO2(110): A Discussion of the Sabatier Principle and Its Role in Electrocatalysis
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DOI：
10.1021/jacs.8b09657
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发表时间：
2018-12-19
影响因子：
15
通讯作者：
Suntivich, Jin
中科院分区：
文献类型：
--
作者：
Kuo, Ding-Yuan;Paik, Hanjong;Suntivich, Jin
本文报道了RuO_2（110）表面上氢氧化物（OHad）和氧化物（O-ad）的实验电吸附自由能，它们对pH的依赖性，以及它们与析氧反应（OER）电催化的关系。Sabatier原理预测，当中间体稳定性适中时，催化剂最具活性，所述中间体稳定性不太强，使得结合的中间体破坏随后的催化循环，也不太弱，使得表面无效。几十年来，研究人员已经使用这个概念来合理化许多OER电催化剂的活性趋势，包括RuO 2，这是最先进的OER催化剂之一。在这篇文章中，我们报告了一个实验评估的Sabatier原则，通过比较氧气的电吸附能量的OER电催化RuO 2的第一次。我们发现RuO_2（110）表面的OHad和O-ad电吸附能与pH有关，并服从标度关系。然而，在包括RuO 2（110）和IrO 2（110）的比较分析中，我们没有观察到OHad和O-ad电吸附能与OER活性之间的直接相关性。我们的研究结果提出了一个问题，是否Sabatier原则可以描述高活性的电催化剂，其中的动力学方面可能会影响电催化更强烈的比电吸附能，它只捕获中间体的热力学，而不是动力学。
We report the hydroxide (OHad) and oxide (O-ad) experimental electroadsorption free energies, their dependences on pH, and their correlations to the oxygen evolution reaction (OER) electrocatalysis on RuO2(110) surface. The Sabatier principle predicts that catalyst is most active when the intermediate stabilization is moderate, not too strong such that the bound intermediate disrupts the subsequent catalytic cycle, nor too weak such that the surface is ineffective. For decades, researchers have used this concept to rationalize the activity trend of many OER electrocatalysts including RuO2, which is among the state-of-the-art OER catalysts. In this article, we report an experimental assessment of the Sabatier principle by comparing the oxygen electroadsorption energy to the OER electrocatalysis for the first time on RuO2. We find that the OHad and O-ad electroadsorption energies on RuO2(110) depend on pH and obey the scaling relation. However, we did not observe a direct correlation between the OHad and O-ad electroadsorption energies and the OER activity in the comparative analysis that includes both RuO2(110) and IrO2(110). Our result raises a question of whether the Sabatier principle can describe highly active electrocatalysts, where the kinetic aspects may influence the electrocatalysis more strongly than the electroadsorption energy, which captures only the thermodynamics of the intermediates and not yet kinetics.