Solving Nafion poisoning of ORR catalysts with an accessible layer: designing a nanostructured core‐shell Pt/C catalyst via a one‐step self‐assembly for PEMFC

Abstract

A core-shell Pt/C@NCL300 catalyst with an accessible layer was designed to recover lost ORR activity and was constructed via a one-step self-assembly process in this paper. A thin porous layer derived from Nafion was first formed on the surface of Pt/C catalyst to create a shell. This first coating successfully separated the Nafion and Pt particles in the catalysts and reducing the negative impact of Nafion on ORR activity and enhancing the fuel cell performance. The newly fabricated Pt/C@NCL300 catalyst exhibited much higher specific activity than the original Pt/C catalyst in RDE tests under the same conditions and were comparable to the activity of Pt/C electrode without Nafion poisoning. Moreover, the fuel cell with Pt/C@NCL300 catalyst exhibited a higher power density without an obvious increase in proton transport and O 2 transport resistance compared to that of a Pt/C fuel cell with a low Pt loading. This result indicates that coating the Pt/C catalyst with a layer accessible for oxygen and protons is a promising way to effectively promote Pt-based catalysts that work under normal operating conditions.

Strengthening Pt/WOx interfacial interactions to increase the CO tolerance of Pt for hydrogen oxidation reaction

“…This phenomenon is similar to that observed in the previous investigation. 34,35 Thus, the electron-deficient state of Pt is due to the modulation of surface WO x . The high-resolution XPS signal of W in Pt/WO x @NC exhibited a lower binding energy compared with that of pristine WO 3 , manifesting the existence of O defects on WO x and the partial reduction of WO 3 (Fig.…”

Investigating Electrode‐Ionomer Interface Phenomena for Electrochemical Energy Applications

“…In catalyst surface modification, a thin porous layer coating on Pt/C was introduced to address Nafion poisoning of ORR catalysts [22a] . When Nafion‐coated Pt/C was heat‐treated at 300 °C, the sulfonate group partially detached from Pt/C, and partial carbonization of the PTFE backbone occurred, resulting in formation of a porous shell layer with a pore size below 3 mm.…”

Cathode Design for Proton Exchange Membrane Fuel Cells in Automotive Applications

“…The power performance at a high current density operation was deteriorated by the modification. Zhou et al [79] have explored a thin porous layer derived from Nafion formed on the surface of Pt/C catalyst to create a shell to reduce the ionomer poisoning and improve the oxygen accessibility. The experimental results demonstrated a very thin coating that helped to separate the Nafion ionomer and Pt particles in the catalysts exhibiting enhanced fuel cell performance.…”