Interfacial Electronic Coupling of NC@WO₃‐W₂C Decorated Ru Clusters as a Reversible Catalyst toward Electrocatalytic Hydrogen Oxidation and Evolution Reactions

Abstract

Designing a bifunctional catalyst for hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER) is significant toward developing sustainable hydrogen-electric conversion systems. Herein, a cost-effective bifunctional catalyst, Ru/N-doped Carbon@WO 3 -W 2 C (Ru/NC@WOC), was developed via co-precipitation and polyol reduction. Ru/NC@WOC showed superior HOR/HER activity in alkaline solution in comparison with commercial Pt/C. HOR electrochemical tests showed that the mass activity at 0.05 V (1.96 mA mg À 1 Ru ) and exchange-current density were 7.5 and 1.2 times that of Pt/C. Additionality, Ru/NC@WOC exhibited up 30-fold HOR activity in mass activity compared with benchmark Ru/C. Moreover, it also displayed exceptional electrocatalytic HER with overpotentials of 31 mV at 10 mA cm À 2 and 119 mV at 100 mA cm À 2 , surpassing Pt/C, benchmark Ru/C, and most of the previously reported electrocatalysts. The outstanding catalytic activity of Ru/ NC@WOC probably arises from the synergy between Ru and NC@WOC matrix, suitable hydrogen binding energy, and highly conductive substrate. Thus, this work may pave a new avenue to fabricate low-cost bifunctional HOR/HER catalysts for alkaline fuel cells and water electrolyzer.

RuP Nanoparticles Supported on N, O Codoped Porous Hollow Carbon for Efficient Hydrogen Oxidation Reaction

“…As shown in Figure S24a in the Supporting Information, the E H‐desorption of RuP is close to that of Ru and slightly negative than commercial Pt/C, indicating that the HBE of RuP is close to that of Ru and slightly lower than commercial Pt/C. [ 8c,41 ] While RuP/NOC exhibits the higher CO stripping peak potential (Figure S24b, Supporting Information), indicating relatively weaker OH adsorption than that of Ru/NOC and Ru/C. [ 42 ] Both results are consistent with our DFT calculation results well.…”

Electronic Modulation of Pt Nanoparticles on Ni3N–Mo2C by Support-Induced Strategy for Accelerating Hydrogen Oxidation and Evolution

“…8,46 In previous studies, the H upd peak's potential has a direct correlation with HBE. 46,47 As illustrated in Figure 3a, 29,50 To further confirm whether the H 2 can be used as a reductant to reduce Pt(IV) in the precursor solution at ambient temperature, ICP-AES was performed. We detected only a small amount of Pt with 0.42 wt % (Table S1) without an H 2 environment, and the catalyst presented a minimal HOR activity.…”

“…We detected only a small amount of Pt with 0.42 wt % (Table S1) without an H 2 environment, and the catalyst presented a minimal HOR activity. Instead, 6.39 wt % Pt was deposited on 47 Next, we investigated the polarization curves of the target catalyst at different rotating speeds, where the plateau current density grows with increasing rotation speed owing to improved mass transport (Figure S13). 51 We also show the mass transportcorrected kinetic current density of these catalysts (Figure 3c).…”

“…Cyclic voltammetry (CVs) curves were recorded in N 2 -saturated 0.1 M KOH solution to study hydrogen adsorption/desorption behaviors to understand the alkaline HOR mechanism. The CVs between 0 and 0.45 V vs RHE corresponded to the hydrogen region, which was in agreement with the hydrogen under-potential deposition (H upd ) region of Pt. , In previous studies, the H upd peak’s potential has a direct correlation with HBE. , As illustrated in Figure a, a negative shift was found for the H upd peak’s potential from Pt/Ni 3 N (0.312 V), Pt/C (0.301 V), Pt/Mo 2 C (0.247 V), to Pt/Ni 3 N–Mo 2 C (0.218 V), suggesting Pt/Ni 3 N–Mo 2 C has weaker hydrogen-bonding sites that lead to faster HOR kinetics . However, Ni 3 N–Mo 2 C showed unobvious hydrogen adsorption/desorption processes, indicating that Pt is the predominant activity center and served as an active site for the hydrogen intermediate. , Besides, the highest CV charge of Pt/Ni 3 N–Mo 2 C is attributed to the better Pt dispersion and stability on Ni 3 N–Mo 2 C supports.…”

Self-supported porous heterostructure WC/WO3−x ceramic electrode for hydrogen evolution reaction in acidic and alkaline media

“…Tungsten oxide is an n-type semiconductor material of transition metal oxides. It attracts strong attention in electrocatalysis because of its stability, abundant resources, and environmentally friendly nature [5,[26][27][28]. Nevertheless, the electrocatalytic performance of hexavalent WO 3 suffers from the large bandgap, resulting in poor electronic conductivity [29,30].…”