Important Progress in Surface Electrocatalysis Published in “Journal of The American Chemical Society”
Recently, Prof. Zhong-Qun Tian, the chief scientist of iChEM, Member of the Chinese Academy of Sciences, and Prof. Dongping Zhan published their important progess in surface electrolysis in Journal of The American Chemical Society titled as “Mobility and Reactivity of Oxygen Adspecies on Platinum Surface” .
The adsorption, desorption, mobility and reactivity of the adspecies on the surface of catalysts are central to the surface science and heterogeneous catalysis. Faradaic adsorption and desorption are surface processes involving electron transfer. Despite the extensive investigation of the adsorption of oxgen adspecies and carbon monoxide (CO) on Pt surface over the last century, these processes remain as the key issues of fuel cells and water electrolysis. Although surface mobility of oxygen adspecies produced by the dissociative adsorption of water is important in electrocatalysis, the quantitative measurement of such a property of oxygen adspecies have rarely been reported probably due to the complexity of solid/liquid interface as well as the lack of applicable experimental techniques.
By employing nanoelectrode and ultramicroelectrode techniques, we have observed the surface mobility of oxygen adspecies produced by the dissociative adsorption of H2O and the surface reaction between the oxygen adspecies and the preadsorbed CO on the Pt surface. The desorption charge of oxygen adspecies on a Pt nanoelectrode has been found to be in proportion to the reciprocal of the square root of scan rate. Using this information, the apparent surface diffusion coefficient of oxygen adspecies has been determined to be (5.61 ± 0.84) × 10-10cm2/s at 25 °C. During the surface oxidation of CO, two current peaks are observed, which are attributed to CO oxidation at the Pt/electrolyte interface and the surface mobility of the oxygen adspecies on the adjacent Pt surface, respectively. These results demonstrate that the surface mobility of oxygen adspecies plays an important role in the antipoisoning and reactivation of Pt catalyst.
The financial support of the National Natural Science Foundation of China (Grants 21327002, 91323303, 21573054, 21321062) is appreciated.
More details please check http://pubs.acs.org/doi/abs/10.1021/acs.accounts.6b00336
