Carbide-Supported PtRu Catalysts for Hydrogen Oxidation Reaction in Alkaline Electrolyte

Abstract

Owing to the sluggish kinetics of the hydrogen oxidation reaction (HOR) in alkaline electrolyte, it is considered a limiting reaction for the development of anion-exchange membrane fuel cell (AEMFC) technology. Studies of alkaline HOR catalysis mainly focus on carbon-supported nanoparticles, which have weak metal–support interactions. In this contribution, we present a unique support based on transition metal carbides (TMCs = Mo2C, Mo2C–TaC, and Mo2C–W2C) for the HOR. PtRu nanoparticles are deposited onto the TMC supports and are characterized by a variety of analytical techniques. The major findings are (i) experimental and theoretical evidence for strong-metal support interaction by both X-ray absorption near-edge structure and density functional theory, (ii) the kinetic current density (j k,s) @25 mV of PtRu/Mo2C–TaC catalyst are 1.65 and 1.50 times higher than that of PtRu/Mo2C and PtRu/Mo2C–W2C, respectively, and (iii) enhanced “tethering” of PtRu nanoparticles on TMC supports. Furthermore, the AEMFC based on the PtRu/Mo2C–TaC anode exhibited a peak power density of 1.2 W cm–2 @70 °C, opening the doors for the development of advanced catalysts based on engineering support materials.

Improved Durability and Activity in Pt/Mo2C Fuel Cell Cathodes by Magnetron Sputtering of Tantalum

“…Such effects have previously been reported for similar systems of platinum group metals in strong contact with ceramic phases. Examples include electron donation by TaC to Pt and electron withdrawal and modulated adsorption from Pd in contact with CeO 2 for enhanced electrocatalysis [71,72] …”

Recent Advances in Electrocatalysts for Alkaline Hydrogen Oxidation Reaction

“…A novel IrNi@PdIr/C core-shell electrocatalyst (Figure 10f) was prepared by Shao's group through a galvanic replacement reaction. [135] Electrocatalytic test results show the mass and specific activities of IrNi@PdIr/C at 50 mV are 2.1 and 2.2 times higher than commercial Pt/C, respectively. The excellent HOR activity of IrNi@PdIr/C mainly ascribes to the weakening of the hydrogen binding to the PdIr shell induced by the IrNi core.…”

“…Moreover, the effect of catalyst-support interaction on HOR was systematically studied by Dekel and co-workers. [135] First, they deposited PtRu catalysts on transition metal carbides (TMC) supports including Mo 2 C, Mo 2 C-TaC, and Mo 2 C-W 2 C. The selection of TMC is mainly based on their similar electronic and catalytic properties to those of platinum group metals (PGMs), which can lead to a strong interaction between TMC and PGM. [146] HOR results (Figure 11h) show that the PtRu/Mo 2 C-TaC exhibits the highest kinetic current density at 25 mV, and it is 1.65 and 1.5 times higher than those of PtRu/Mo 2 C and PtRu/Mo 2 C-W 2 C, respectively.…”

“…Few studies were reported for exploration of using membrane electrode assembly (MEA) and overall fuel cell. [37][38][39][40][41] Therefore, it is uncertain whether the catalysts can be applied to practical applications. Some reviews have reported HOR in alkaline media.…”

“…Copyright 2019, Elsevier; Panel (g): Reproduced with permission [144]. Copyright 2019, ACS; Panels (h-j) Reproduced with permission [135]. Copyright 2021, ACS.…”