Unexpected Behavior of the Hydrogen Oxidation Reaction on Palladium in Alkaline Solution: A Feasible Kinetic Explanation

Abstract

The hydrogen oxidation reaction was studied on a thin film palladium electrode supported on a gold substrate in alkaline solution. The hydrogen absorption process was analyzed by open circuit potential transient and the current -overpotential dependences were obtained by chronoamperometry at different rotation rates in a solution saturated with hydrogen. The results obtained show an unexpected profile at low overpotentials, where current decreases as rotation rate increases. A kinetic mechanism was proposed to interpret this behavior and the corresponding equations were derived. They were used to correlate the results, with a good agreement between the experimental and fitted curves.

Self-Optimized Ligand Effect in L12-PtPdFe Intermetallic for Efficient and Stable Alkaline Hydrogen Oxidation Reaction

“…The widely accepted HBE theory, that is, the HOR catalytic activity of the catalyst is solely related to its adsorption strength of hydrogen, and the peak potential of under potential deposition hydrogen (H ‑upd ) is corresponding to the HBE value. ,,, Hence, it demonstrates that (Pt 0.9 Pd 0.1 ) 3 Fe/C exhibits similar HBE with Pt 3 Fe/C, and the stress contraction discrepancy between (Pt 0.9 Pd 0.1 ) 3 Fe/C and Pt 3 Fe/C is not reflected in the CV curves. In addition, it is worth noting that the enhanced peak intensity at ∼0.03 V is related to the electrochemical hydrogen incorporated into the Pd’s lattice and the formation of PdH x . − The electrochemical behavior of (Pt 0.9 Pd 0.1 ) 3 Fe/C is intrinsically affected by PdH x due to the Pd-substitution. Therefore, the ligand effect of PdH x may play a major role in the HOR catalytic performance regulation rather than the compression stress.…”

Tuning hydrogen sorption properties of Pd by its alloying with Ru, Rh, and Pt: the study of binary alloys in concentrated alkaline media

“…Therefore, in the literature, there are many publications dedicated to hydrogen electrosorption in Pd-based electrodes from acidic water solutions [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Unfortunately, not many researchers address the problem of hydrogen sorption in alkaline media [22][23][24][25][26][27][28][29][30][31][32][33][34][35] being confined predominantly to Pd examination in diluted solutions.…”