Study on Attenuation Mechanism and Durability Improvement of Platinum-Carbon Catalysts for Proton Exchange Membrane Fuel Cells

Abstract

The relationship between Pt particle size and activity and durability of Pt/C electrocatalysts on rotating disk electrodes is established and the results show that Pt/C electrocatalysts with particle size over 3.5 nm have excellent resistance to Pt particle decay and carbon corrosion. Further, the research results on the mechanism of Pt particle decay and carbon corrosion show that the Pt particle attenuation is composed of 80% Ostwald ripening and 20% particle agglomeration, and the carbon corrosion is affected by the catalytic action of Pt particles. Therefore, the above results show that regulating the Pt particle size to 3.5–4.0 nm can improve the durability of Pt/C electrocatalysts on RDE. To verify the accuracy of this conclusion and determine the optimal particle size range in practical application, single cells with 5 × 5 cm 2 is assembled to evaluate the performance and durability of cathode Pt/C electrocatalysts under H 2 /air. The results show that cathode Pt/C electrocatalysts with particle size between 3.5 nm and 3.8 nm have high single cell performance (2.3 A cm −2 @0.65 V) and durability (A loss of 15 mV@0.8 A cm −2 after 30000 cycles). These findings reveal the attenuation mechanism of Pt/C electrocatalysts and provide ideas for the development of high-durability Pt-based electrocatalysts for practical applications.