Ding Mengning, Zhong Guangyan, Zhao Zipeng, Huang Zhihong, Li Mufan, Shiu Hui-Ying, Liu Yuan, Shakir Imran, Huang Yu, Duan Xiangfeng
Department of Materials Science and Engineering, Department of Chemistry and Biochemistry, and California Nanosystems Institute, University of California, Los Angeles, California 90095, United States.
Sustainable Energy Technologies Centre, College of Engineering, King Saud University, Riyadh 11421, Kingdom of Saudi Arabia.
ACS Cent Sci. 2018 May 23;4(5):590-599. doi: 10.1021/acscentsci.8b00082. Epub 2018 Apr 25.
The development of future sustainable energy technologies relies critically on our understanding of electrocatalytic reactions occurring at the electrode-electrolyte interfaces, and the identification of key reaction promoters and inhibitors. Here we present a systematic in situ nanoelectronic measurement of anionic surface adsorptions (sulfates, halides, and cyanides) on ultrathin platinum nanowires during active electrochemical processes, probing their competitive adsorption behavior with oxygenated species and correlating them to the electrokinetics of the oxygen reduction reaction (ORR). The competitive anionic adsorption features obtained from our studies provide fundamental insight into the surface poisoning of Pt-catalyzed ORR kinetics by various anionic species. Particularly, the unique nanoelectronic approach enables highly sensitive characterization of anionic adsorption and opens an efficient pathway to address the practical poisoning issue (at trace level contaminations) from a fundamental perspective. Through the identified nanoelectronic indicators, we further demonstrate that rationally designed competitive anionic adsorption may provide improved poisoning resistance, leading to performance (activity and lifetime) enhancement of energy conversion devices.
未来可持续能源技术的发展严重依赖于我们对电极 - 电解质界面发生的电催化反应的理解，以及对关键反应促进剂和抑制剂的识别。在此，我们展示了在活性电化学过程中对超薄铂纳米线上阴离子表面吸附（硫酸盐、卤化物和氰化物）进行的系统原位纳米电子测量，探究它们与含氧物种的竞争吸附行为，并将其与氧还原反应（ORR）的电动力学相关联。我们研究中获得的竞争性阴离子吸附特征为各种阴离子物种对铂催化的ORR动力学的表面中毒提供了基本见解。特别是，独特的纳米电子方法能够对阴离子吸附进行高度灵敏的表征，并从根本角度开辟了一条解决实际中毒问题（痕量污染情况）的有效途径。通过所识别的纳米电子指标，我们进一步证明，合理设计的竞争性阴离子吸附可提供更高的抗中毒能力，从而提高能量转换装置的性能（活性和寿命）。
