原位双光束符合二次谐波产生作为电化学界面空间分辨动力学的探针。

In situ dual-beam coincidence second harmonic generation as a probe of spatially resolved dynamics at electrochemical interfaces.

作者信息

Pozniak Boguslaw, Scherson Daniel A

机构信息

Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106-7078, USA.

出版信息

J Am Chem Soc. 2004 Nov 17;126(45):14696-7. doi: 10.1021/ja046809j.

DOI:10.1021/ja046809j

PMID:15535675

Abstract

In situ dual-beam coincidence second harmonic generation was used to monitor spatially resolved dynamics at the Pt(111)/CO-saturated 0.1 M HClO4 interface. The results obtained showed that, for potential steps from 30 to about 870 mV vs RHE, the full electrooxidation of CO as evidenced from SHG occurred at different times for the two areas of the Pt(111) surface probed by the beams. On this basis, the diffusional rates of adsorbed CO cannot be assumed to be generally large enough as to render the entire surface in a homogeneous state, as invoked by the mean field approximation model.

摘要

原位双光束符合二次谐波产生技术被用于监测Pt(111)/CO饱和的0.1 M高氯酸溶液界面处的空间分辨动力学。所得结果表明，相对于可逆氢电极，当电位从30 mV跃升至约870 mV时，由二次谐波产生所证明的CO的完全电氧化在光束探测的Pt(111)表面的两个区域发生的时间不同。在此基础上，如平均场近似模型所假设的那样，不能认为吸附态CO的扩散速率通常足够大，以至于使整个表面处于均匀状态。