Hydrogenated Boride-Assisted Gram-Scale Production of Platinum–Palladium Alloy Nanoparticles on Carbon Black for PEMFC Cathodes: A Study from a Practical Standpoint
Saisai Gao, Haidong Zhao, Pengfei Gao, Jinglei Bi, Dan Liŭ, Daolong Zhu, Bin Wang, Shengchun Yang
Abstract
Platinum–palladium (PtPd) alloy catalysts with high durability are viable substituents to commercial Pt/C for proton exchange membrane fuel cells (PEMFCs). Herein, a facile approach for gram-scale preparation of PtxPd100–x alloy nanoparticles on carbon black is developed. The optimized Pt54Pd46/B–C catalyst shows a mass activity (MA) of 0.549 A mgPt–1 and a specific activity (SA) of 0.463 mA cm–2 at the rotating disk electrode (RDE) level, which are 3.4 and 1.9 times those of commercial Pt/C, respectively. In H2/O2 and H2/air PEMFCs, the membrane electrode assembly (MEA) with Pt54Pd46/B–C achieves peak power densities of 2.33 and 1.04 W cm–2, respectively, and shows negligible performance degradation after 100 h of running in H2/O2 conditions. Moreover, the MA of MEA with Pt54Pd46/B–C in H2/O2 PEMFC reaches 0.978 A mgPt+Pd–1 beyond the 2020 target of the Department of Energy (DOE) of 0.44 A mgPt–1. After 30k cyclic voltammetry cycles in PEMFC, the MA loss and cell voltage loss of MEA with Pt54Pd46/B–C are well within the DOE 2020 target. Density functional theory calculations reveal that the PtPd(111) surface can weaken the adsorption of *OOH and *OH compared to the Pt(111) surface, indicating that Pt54Pd46/B–C is more energetically favorable for the oxygen reduction reaction (ORR) than commercial Pt/C. This study offers a new approach for batch preparation of PtPd alloy-based catalysts for PEMFCs.