Sulfur Dioxide-Tolerant Oleylamine-Modified Pt/C Catalysts toward Oxygen Electroreduction

Abstract

The Pt-based oxygen reduction reaction (ORR) catalyst for proton exchange membrane fuel cells (PEMFC) is highly prone to being poisoned and deactivated by air impurities SO₂. It is crucial to enhance its SO₂ tolerance. In this paper, we found that modifying the surface of Pt particles with oleylamine (OAm) can enhance the resistance to SO₂ poisoning. Detailed investigations demonstrate that the introduction of OAm is beneficial for the oxidation of SO_2ad, which accelerating the regeneration of the Pt surface. After SO₂ poisoning, the OAm-Pt/C catalyst maintains 71% ORR mass activity at 0.9 V and 60% electrochemical surface area (ECSA), much better than the Pt/C (38% mass activity, 30% ECSA remained). That indicates that the SO₂ tolerance of Pt after OAm modification is significantly improved. The OAm on Pt surfaces introduces a spatial hindrance effect, which physically impedes the access and subsequent adsorption of SO₂ on the Pt active sites, improving the SO₂ tolerance of other state-of-the-art Pt-based catalysts.

Keywords: Oxygen reduction reaction, Platinum-based catalyst, Sulfur dioxide tolerance

DOI: 10.7176/CMR/18-1-03

Publication date: February 28^th 2026