Influence of counter electrode material during accelerated durability test of non-precious metal electrocatalysts in acidic medium

Significant progress has been made in the development of non-precious metal electrocatalysts (NPMEs) during the past decade. Correspondingly, there is an urgent demand for an appropriate measurement method to be established for the reliable evaluation of NPMEs. In this study, platinum and graphite counter electrodes were used to investigate the impact of counter electrode material on the accelerated durability testing (ADT) of NPMEs in acidic medium. Platinum used as the counter electrode in a traditional three-electrode electrochemical cell was found to dissolve in acidic medium and re-deposit on NPME coated on the working electrode during ADT. Such re-deposition causes the oxygen reduction reaction (ORR) performance of NPMEs to remarkably improve, and thus will seriously mislead our judgment of NPMEs if we are unaware of it. The phenomenon can be avoided using a graphite counter electrode.

Graphical AbstractGraphite rather than platinum should be used as the counter electrode for the evaluation of non-precious metal electrocatalysts using accelerated durability tests in acidic media, because Pt dissolves and deposits on the electrocatalyst, affecting the assessment.Figure optionsDownload as PowerPoint slide