In-operando surface-sensitive probing of electrochemical reactions on nanoparticle electrocatalysts: Spectroscopic characterization of reaction intermediates and elementary steps of oxygen reduction reaction on Pt
In-operando surface-sensitive probing of electrochemical reactions on nanoparticle electrocatalysts: Spectroscopic characterization of reaction intermediates and elementary steps of oxygen reduction reaction on Pt
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DOI：
10.1016/j.jcat.2021.02.009
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发表时间：
2021-04
影响因子：
7.3
通讯作者：
Sean T. Dix;S. Linic
中科院分区：
文献类型：
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作者：
Sean T. Dix;S. Linic
在本文中，我们提出了一个在operando光谱研究的反应中间体参与ORR通电Pt纳米粒子电催化剂。为了实现这一点，我们合成了Ag-Pt核-壳纳米颗粒，其包含均匀沉积在较大Ag核（~60 nm）上的Pt薄壳（~1 nm）。我们表明，这些纳米结构是理想的平台，在operando等离子体增强拉曼光谱（PERS）的ORR的Pt。我们结合这些PERS研究与DFT计算分配测得的振动光谱相关的表面中间体作为电催化剂电位的函数。通过使用脱氧和重氧（O2-18）饱和电解质进行PERS测量，进一步验证和确认这些振动分配。这些研究使我们能够识别的关键反应中间体（OH，O2，OOH，和H2O）的存在下作为Pt表面上的操作电压的函数，并推导出电压依赖性的基本步骤的反应机制。
In this paper we present an in-operando spectroscopic study of the reaction intermediates involved in ORR on electrified Pt nanoparticle electrocatalysts. To accomplish this, we have synthesized Ag-Pt core–shell nanoparticles, that contain a thin shell of Pt (~1 nm) uniformly deposited on a larger Ag core (~60 nm). We show that these nanostructures are ideal platforms for in-operando Plasmon Enhanced Raman Spectroscopy (PERS) of ORR on Pt. We combined these PERS studies with DFT calculations to assign the measured vibrational spectra to relevant surface intermediates as a function of electrocatalyst potential. These vibrational assignments were further verified and validated by performing PERS measurements using de-oxygenated and heavy oxygen (O2-18) saturated electrolyte. These studies allowed us to identity the presence of critical reaction intermediates (OH, O2, OOH, and H2O) as the function of operating voltage on the Pt surface and derive voltage-dependent elementary step mechanisms of the reaction.