Environmental TEM Study of Electron Beam Induced Electrochemistry of Pr0.64Ca0.36MnO3 Catalysts for Oxygen Evolution
Environmental TEM Study of Electron Beam Induced Electrochemistry of Pr0.64Ca0.36MnO3 Catalysts for Oxygen Evolution
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DOI：
10.1021/jp511628c
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发表时间：
2015-02
影响因子：
3.7
通讯作者：
S. Mildner;M. Beleggia;Daniel Mierwaldt;T. Hansen;J. Wagner;S. Yazdi;T. Kasama;J. Ciston;Yimei Zhu;C. Jooss
中科院分区：
文献类型：
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作者：
S. Mildner;M. Beleggia;Daniel Mierwaldt;T. Hansen;J. Wagner;S. Yazdi;T. Kasama;J. Ciston;Yimei Zhu;C. Jooss
环境透射电子显微镜（ETEM）研究为收集与反应物接触的电极的电子状态的原子尺度信息提供了巨大的潜力。由于高能电子束的影响，它也提出了巨大的挑战。在本文中，我们对Pr0.64Ca0.36MnO3 （PCMO）薄膜电催化剂在与水蒸气接触时的水裂解和析氧进行了ETEM研究。我们通过离轴电子全息和静电建模表明，由于二次电子发射，电子束会产生正的电样品电位。电势的值取决于初级电子通量、样品的电导率和接地以及气体性质。我们提出的证据表明，两个观察到的电化学反应是由一伏特数量级的束流诱导静电电位驱动的。第一个反应是贫氧无定形PCMO的阳极氧化，导致…
Environmental transmission electron microscopy (ETEM) studies offer great potential for gathering atomic scale information on the electronic state of electrodes in contact with reactants. It also poses big challenges due to the impact of the high energy electron beam. In this article, we present an ETEM study of a Pr0.64Ca0.36MnO3 (PCMO) thin film electrocatalyst for water splitting and oxygen evolution in contact with water vapor. We show by means of off-axis electron holography and electrostatic modeling that the electron beam gives rise to a positive electric sample potential due to secondary electron emission. The value of the electric potential depends on the primary electron flux, the sample’s electric conductivity and grounding, and gas properties. We present evidence that two observed electrochemical reactions are driven by a beam induced electrostatic potential of the order of a volt. The first reaction is an anodic oxidation of oxygen depleted amorphous PCMO which results in recrystallization of...