Ultrafine jagged platinum nanowires enable ultrahigh mass activity for the oxygen reduction reaction
Mufan Li, Zipeng Zhao, Tao Cheng, Alessandro Fortunelli, Chih-Yen Chen, Rong Yu, Qinghua Zhang, Lin Gu, Boris V. Merinov, Zhaoyang Lin, Enbo Zhu, Ted H. Yu, Qingying Jia, Jinghua Guo, Liang Zhang, William A. Goddard III, Yu Huang, Xiangfeng Duan
Abstract
Improving the platinum (Pt) mass activity for the oxygen reduction reaction (ORR) requires optimization of both the specific activity and the electrochemically active surface area (ECSA). We found that solution-synthesized Pt/NiO core/shell nanowires can be converted into PtNi alloy nanowires through a thermal annealing process and then transformed into jagged Pt nanowires via electrochemical dealloying. The jagged nanowires exhibit an ECSA of 118 square meters per gram of Pt and a specific activity of 11.5 milliamperes per square centimeter for ORR (at 0.9 volts versus reversible hydrogen electrode), yielding a mass activity of 13.6 amperes per milligram of Pt, nearly double previously reported best values. Reactive molecular dynamics simulations suggest that highly stressed, undercoordinated rhombus-rich surface configurations of the jagged nanowires enhance ORR activity versus more relaxed surfaces.
Group Members
William A. Goddard III
Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics; Director, Materials and Process Simulation Center, Caltech
Boris Merinov
Lead Scientist, Director of Energy Conversion and Storage Technologies
Alessandro Fortunelli
Visiting Guest, CNR
Ted Yu
Volunteer
Li, M., Zhao, Z., Cheng, T., Fortunelli, A., Chen, C., Yu, R., Zhang, Q., Gu, L., Merinov, B. V., Lin, Z., Zhu, E., Yu, T. H., Jia, Q., Guo, J., Zhang, L., III, W. A. G., Huang, Y., & Duan, X. (2016). Ultrafine jagged platinum nanowires enable ultrahigh mass activity for the oxygen reduction reaction. *Science*, *354*(6318), 1414-1419. https://doi.org/10.1126/science.aaf9050