Mechanistic Study of the Hydrogen Oxidation/Evolution Reaction over Bimetallic PtRu Catalysts

Abstract

In this work, the activity of bimetallic PtRu/C with varying amounts of Ru for the hydrogen oxidation/evolution reactions (HOR/HER) was determined. The results demonstrate that surface Ru is not necessary for high activity, which shows that the improved activity of the bimetallic PtRu comes from the electronic interaction of Ru with Pt and the tuning of the hydrogen binding energy (HBE). Using the charge transfer coeffiecient from Butler-Volmer fitting and kinetic modeling, it was determined that Ru affects the HOR/HER mechanism in two ways: changing the pathway from Tafel-Volmer to Heyrovsky-Volmer, and lowering of the activation barrier of the Volmer step. Utilizing catalysts with Heyrovsky-Volmer(RDS) mechanism as well as focusing on tuning the HBE might help improve the activity of non-precious metal catalysts; allowing PGM-free fuel cells to become economically viable.

Durability of anion exchange membrane water electrolyzers

“…38 Still, as far as we know, the best alkaline HER catalysts are platinum-based alloys or defects-doped platinum. [39][40][41][42][43] As for OER catalysts for AEMWEs, a large variety of metals show high OER activity and corrosion stability in an alkaline environment. The most promising transition metals are found in the fourth row of the periodic table (3d elements).…”

Lattice‐Confined Ir Clusters on Pd Nanosheets with Charge Redistribution for the Hydrogen Oxidation Reaction under Alkaline Conditions

“…[1][2][3][4] Hydrogen fuel cells is one of the most promising hydrogen utilization technologies for highly efficient energy conversion. [5,6] Compared with the protonexchange-membrane fuel cells (PEMFCs), alkaline exchange membrane fuel cells (AEMFCs) possess their unique advantages, such as the broader selectivity of cell components, the long-term stability under alkaline conditions, and the facile use of non-precious metal electrocatalysts with Pt-like activity for the cathodic oxygen reduction reaction (ORR). [7][8][9][10][11][12][13] However, the sluggish kinetics of the hydrogen oxidation reaction (HOR) as a nonnegligible issue has hindered the development of AEMFCs.…”

Bimetallic Mixed Clusters Highly Loaded on Porous 2D Graphdiyne for Hydrogen Energy Conversion

“…According to literatures, multi‐component metal catalysts with adjustable electronic structure and composites generally show higher catalytic performance than mono‐component ones. [ 13 ] For example, Li and co‐workers reported that the bimetallic iron‐cobalt layered double‐hydroxide showed enhanced HER catalytic performances because of the greatly facilitated charge transport kinetics, increased electrochemical active surface area and number of active sites. [ 14 ] Liu et al.…”