Hydrogenated Boride-Assisted Gram-Scale Production of Platinum-Palladium Alloy Nanoparticles on Carbon Black for PEMFC Cathodes: A Study from a Practical Standpoint.

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 PtPd alloy nanoparticles on carbon black is developed. The optimized PtPd/B-C catalyst shows a mass activity (MA) of 0.549 A mg and a specific activity (SA) of 0.463 mA cm at the rotating disk electrode (RDE) level, which are 3.4 and 1.9 times those of commercial Pt/C, respectively. In H/O and H/air PEMFCs, the membrane electrode assembly (MEA) with PtPd/B-C achieves peak power densities of 2.33 and 1.04 W cm, respectively, and shows negligible performance degradation after 100 h of running in H/O conditions. Moreover, the MA of MEA with PtPd/B-C in H/O PEMFC reaches 0.978 A mg beyond the 2020 target of the Department of Energy (DOE) of 0.44 A mg. After 30k cyclic voltammetry cycles in PEMFC, the MA loss and cell voltage loss of MEA with PtPd/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 PtPd/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.