A Universal Strategy to Enhance Polarization Performance and Anode Reversal Tolerance by Polyaniline-Coated Carbon Support for Proton Exchange Membrane Fuel Cells.

ABSTRACT

Anode cell reversal typically leads to severe carbon corrosion and catalyst layer collapse, which significantly compromises the durability of proton exchange membrane fuel cells. Herein, three types of commercial carbon supports with various structures are facilely coated by polyaniline (PANI) and subsequently fabricated into reversal-tolerant anodes (RTAs). Consequently, the optimized PANI-coated catalyst RTAs demonstrate enhanced polarization performance and improved reversal tolerance compared to their uncoated counterparts, thus confirming the universality of this coating strategy. Essentially, the surface engineering introduced by PANI coating incorporates abundant N-groups and enhances coulombic interactions with ionomer side chains, which in turn reduces lower carbon exposure, promotes more uniform Pt deposition, and ensures better ionomer distribution. Accordingly, the membrane-electrode-assembly containing the Pt/PANI/XC-72R-1+IrO2 RTA presents a 100 mV (at 2500 mA cm-2) polarization performance improvement and 26-fold reduction in the degradation rate compared to the uncoated counterpart. This work provides a universal strategy for developing durable anodes and lays the groundwork for the practical fabrication of high-performance, low-degradation RTA.