Hydrogen Evolution Electrocatalysis on AgPd(111) Alloys

Abstract

Recent studies on AuPd(111) alloy surfaces display unexpected hydrogen evolution reaction activities-a unique activity of AuPd alloys with surface fractions of~20% Pd was found. We investigated if this phenomenon also occurs with AgPd alloys. We first deposited Pd on a Ru (0001) substrate. After annealing, cyclic voltammetry investigations showed the same characteristics as Pd (111) single crystals. During Ag deposition, cyclic voltammetry experiments disclose underpotential deposition of Ag on the Pd film just as on Pd(111). AgPd alloys were formed by further annealing, and strong enrichment of Ag at the surface is observed. Using this approach, we prepared various bulk compositions at a film thickness of 20 monolayers. Most AgPd alloys show a higher electrocatalytic activity than Ag or Pd alone. The activity trends match those seen with AuPd alloys.

Alkaline water-splitting reactions over Pd/Co-MOF-derived carbon obtained via microwave-assisted synthesis

“…24 This assumption agrees with the study of free energy diagram of HER in alkaline conditions, which proved that Volmer-Heyrovsky mechanism dominate. 25 However, high Tafel slopes (160-266 mV dec À1 ) obtained here than the theoretical values for Volmer and Heyrovsky processes, have previously been ascribed to high hydrogen adsorption onto the active sites of polycrystalline Pd electrocatalysts, as supplementary reaction step, 26,27 and are also reported in the compared literature (see Table 3).…”

Vine Shoots and Grape Stalks as Carbon Sources for Hydrogen Evolution Reaction Electrocatalyst Supports

“…The obtained values suggest that the Volmer step is the rate-determining step (RDS) of the process. Tafel slope value deviations from the theoretical value of 0.120 V dec −1 for the Volmer step as the RDS [34] have been previously reported and explained by the mentioned absorption of hydrogen into the Pd bulk [2,35]. Additionally, it was observed that b values obtained at the three electrocatalysts increased with temperature, which is also reflected in a small decrease of α.…”

Bifunctional Behavior of Pd/Ni Nanocatalysts on MOF‐Derived Carbons for Alkaline Water‐splitting

“…The higher b c values of the nanocatalysts than the theoretical values ( ca . 120 mV dec −1 ) [49, 50] were attributed to H's surface coverage on polycrystalline Pd nanocatalyst [51]. High b c values were also obtained for compared literature with the nanocatalysts toward the HER, summarized in Table 2.…”