Pt/C catalysts synthesized in a commercial particle atomic layer deposition system enabling improved durability in fuel cells

Abstract

Particle atomic layer deposition (ALD) is an emerging method for engineering 3D materials, such as powders, for energy applications. In our study, we employ a commercially available and scalable particle ALD system to synthesize Pt/C electrocatalysts for fuel cells. Our method yields Pt/C catalysts characterized by highly dispersed platinum nanoparticles with a narrow particle size distribution of 2.2 ± 0.5 nm for 30 wt% Pt and 2.6 ± 0.6 nm for 40 wt% Pt, as verified through transmission electron microscopy and X-ray diffraction analysis. The performance of the ALD-synthesized catalysts is benchmarked against a state-of-the-art catalyst (TEC10V50E), with both catalysts exhibiting similar beginning-of-test performance (1.6 A cm⁻² at 0.65 V) under application-relevant operation conditions (80 °C, 50% relative humidity). After 30 000 voltage cycles, conducted in accordance with the U.S. Department of Energy's accelerated catalyst degradation test, the ALD catalysts demonstrate up to 64% greater electrochemical active surface areas and superior retention of cell performance, with a 34% higher current density at 0.65 V, compared to the reference. Given the scalability of the commercial particle ALD system, these promising results encourage the use of particle ALD as a novel synthesis approach for fuel cell catalyst materials in the industry.