Preparation of CO-tolerant PtRuNi/C ternary electrocatalyst having a composition gradient shell

The carbon-supported PtRuNi/C ternary electrocatalyst having a composition gradient shell was developed using the high-temperature heat treatment and polydopamine protective coating techniques. The fabricated catalyst is a CO-tolerant anode catalyst developed for use in polymer electrolyte membrane fuel cells (PEMFCs). Energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy techniques were used to characterize the catalyst. The results revealed that high-temperature heat treatment led to atomic rearrangement in the shell, resulting in increased Pt content on the catalyst surface and an increased ratio of Ru and Ni in order. The Pt and Ru layers effectively prevent Ni leaching in the acidic environment of the PEMFCs. In addition, a protective coating of polydopamine suppresses the sintering of the catalyst particles when the high-temperature treatment technique is used for catalyst fabrication, thereby preventing the decrease of the active surface area of the catalyst. As a result of the change in the electronic structure of Pt induced by the underlying Ru and Ni atoms, the PtRuNi/C catalyst exhibited enhanced CO tolerance compared to the Pt/C and PtRu/C catalysts as proved by the results from the CO stripping voltammetry and PEMFC test.