Rhodium metal–rhodium oxide (Rh–Rh₂O₃) nanostructures with Pt-like or better activity towards hydrogen evolution and oxidation reactions (HER, HOR) in acid and base: correlating its HOR/HER activity with hydrogen binding energy and oxophilicity of the catalyst

Abstract

Rh–Rh2O3 nanostructures exhibit superior HER and HOR in acid and base; hydrogen binding energy and oxophilicity were found to be the equivalent descriptors for HER/HOR in alkaline medium.

Rhodium Phosphide: A New Type of Hydrogen Oxidation Reaction Catalyst with Non‐Linear Correlated Catalytic Response to pH

“…It can be seen that the percentage of P content is reduced when the upper potential limit becomes more positive (from 0.72 V to 1.12 V). Based on the literature about Rh‐Rh 2 O 3 used for catalyzing HER/HOR, the activity of partial oxidized catalyst (Rh‐Rh 2 O 3 ) is much better than that of Rh 2 O 3 ‐free Rh, we propose that in our Rh 2 P system, the decreased HOR activity is due the oxidation of P species when the upper potential limit becomes more positive. These results demonstrate the P plays an important role during the catalytic process for Rh 2 P/C, in line with those DFT calculations ,…”

Clean rhodium nanoparticles prepared by laser ablation in liquid for high performance electrocatalysis of the hydrogen evolution reaction

“…It is worth to highlight that the presence of the oxide was proposed to have a key role in efficient hydrogen evolution reaction by Rh/Rh 2 O 3 nanostructures bifunctional catalyst in alkaline environment, due to the favoured balancing of the surface properties coming from the weakening of hydrogen binding energy and the increase of oxophilicity and ability of OH À binding. 7 The electrochemical features of E-Rh/C and W-Rh/C (0.5 M H 2 SO 4 , 20 mV s À1 ) under argon saturated solution are similar, with an anodic wave at E pa ¼ 0.70 V vs. reversible hydrogen electrode (RHE), attributed to surface oxidation of metallic Rh to higher oxidation states, i.e. Rh(I)-Rh(III).…”

“…[1][2][3][4] The development of Rh-based nano-catalysts has thus received increasing interest, also by virtue of their compelling properties towards electrocatalysis for energy applications, in particular for the hydrogen evolution reaction (HER). [5][6][7][8][9] To this purpose, Rh nanocrystals are oen obtained by solution-based routes, either one-pot or multi-step, in environments containing salts, carbohydrates, oil, hydrouoric acid or organic solvent, [6][7][8]10,11 by various procedures such as microwave heating, 1 solvothermal, 8 sonochemical 7 or electrochemical synthesis. 1 These methods allow the achievement of the conditions required for the conversion of Rh precursor (e.g., RhCl 3 , Na 3 RhCl 6 or Rh acetate) into metal nanocrystals, typically in the presence of stabilizing agents (oleylamine), strong reducing agents (NaBH 4 ) or high temperature.…”

“…Rh(I)-Rh(III). 7,22 In the backward scan, two cathodic peaks are observed at E pc ¼ 0.60 and 0.32 V vs. RHE, and attributed to stepwise reduction of higher oxidized states to Rh(0). 22 The electrochemical surface area (ESA) of the electrodes was evaluated by anodic CO stripping, [23][24][25] by comparing the cyclic voltammetries (0.5 M H 2 SO 4 , 20 mV s À1 ) under argon saturated solution of the electrodes before and aer exposure treatment with CO (Fig.…”

Enhanced Electrocatalytic Hydrogen Oxidation on Ni/NiO/C Derived from a Nickel‐Based Metal–Organic Framework

“…demonstrated that optimized adsorption of hydroxyl species (OH*) could also promote the overall hydrogen oxidation rate in alkaline electrolytes . Indeed, a number of electrocatalyst systems consisting of two constituents (metals and/or metal oxides) have been reported with enhanced HOR performance with the secondary components showing optimal OH* binding, including Pt‐CeO 2 , Rh‐Rh 2 O 3 , PdNi, and PdCu . Nevertheless, these electrocatalyst systems typically contain platinum group metals (PGMs) and are thus not cost‐effective.…”