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

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 Pt x Pd100–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.

Effective treatment of hydrogen boride sheets for long-term stabilization

“…Several studies have confirmed that HB sheets exhibit semimetal electronic properties, 14 superior catalytic properties, 15–19 and specific reductant properties. 17,20,21 Fujino et al demonstrated the ability of HB sheets to catalyze the production of ethylene from ethanol with high selectivity and long-term stability.…”

“…2 These HB sheets are predicted to exhibit intriguing physical and electronic properties, [3][4][5] making them suitable for a variety of applications including superior batteries, [6][7][8] sensors, 9 hydrogen storage materials, [10][11][12] and current limiters. 13 Several studies have confirmed that HB sheets exhibit semimetal electronic properties, 14 superior catalytic properties, [15][16][17][18][19] and specific reductant properties. 17,20,21 Fujino et al demonstrated the ability of HB sheets to catalyze the production of ethylene from ethanol with high selectivity and long-term stability.…”

“…15,16 Similarly, Gao et al found that a catalyst prepared with HB and Pt exhibited superior electrocatalytic activity and stability against oxygen reduction compared to commercial Pt/C for proton exchange membrane fuel cells. 17,18 In another study, Saad et al reported that a Co 3 O 4 catalyst prepared with HB exhibited excellent performance for oxygen evolution. 19 Moreover, studies have shown that CO 2 can adsorb on hydrogen-deficient HB sheets at approximately 300 K, and CO 2 was converted to CH 4 and C 2 H 6 above 423 K via dissociation and hydrogenation of CO 2 , as well as C-C coupling, even at relatively low temperatures.…”

A Porous Wrinkled Graphitic Carbon as Corrosion‐Resistant Carbon Support for Durable Fuel‐Cell Catalysts

“…[35] Carbon nanotubes and graphene are examples of high graphitization materials, with improved corrosion resistance due to their perfect sp 2 structure; however, this feature can make it difficult for the firm and uniform deposition of Pt NPs due to the lack of anchorage sites. [32] As an alternative, heteroatom doping with N, [36] S [37,38] or B [39] have been used to regulate the charge redistribution of carbon and improve the interactions between Pt and carbon, which is proven to be beneficial for improving the durability of ORR catalysts. Alternatively, non-carbonaceous materials such as metal oxides and carbides have also been explored, but their limited electrical conductivity and lack of porosity could hinder their use as support.…”

Controlling Photoinduced H2 Release from Freestanding Borophane Sheets Under UV Irradiation by Tuning B–H Bonds

“…[24] They can also reduce specific metal ions to form nanocomposites. [25][26][27][28][29] Notably, hydrogen-deficient HB sheets can adsorb CO 2 and convert it into methane and ethane, even at low temperatures (e.g., 423 K). [30] In addition, theoretical modeling and computer simulations demonstrate that HB sheets are promising candidates for certain applications, such as hydrogen-storage materials, [31][32][33][34][35] battery anode materials, [36][37][38][39] highly selective and sensitive sensors, [40,41] current limiters, [42] and photodetectors.…”