Metastable Metal–Alloy Interface in RuNi Nanoplates Boosts Highly Efficient Hydrogen Electrocatalysis

Abstract

Designing a unique metastable interface provides a promising way to achieve high catalytic performance yet remains a great challenge due to the thermodynamics’ unstable nature. In this work, we constructed the stabilized metastable interface between metastable ruthenium–nickel alloy and metastable hexagonal–close-packed nickel via a one-step solvothermal method. The optimized nanocatalyst (denoted as hcp RuNi) shows bifunctional performance toward electrochemical hydrogen oxidation and evolution reactions (HOR/HER). Density functional theory calculations reveal that two different reaction sites at the unique interface contribute to the enhanced HER and HOR performances. This work highlights the important role on interface engineering of metastable materials for highly efficient catalysis.

Electronic Modulation and Mechanistic Study of Ru‐Decorated Porous Cu‐Rich Cuprous Oxide for Robust Alkaline Hydrogen Oxidation and Evolution Reactions

“…Additionally, we found that Ru/Cu−Cu 2 O@C held the strongest OH* adsorption among the four catalysts. Such an enhanced OH* adsorptive behavior favored the capture of OH* species on the Cu 2 O surface, in accord with the CO stripping results (Figure 6g and Figure S20) [47] . Since the dissociation of water was a primary step that directly determined the HER activity, we also calculated the adsorption free energies of H 2 O* for the four catalysts (Figure 6h and Figure S21).…”

“…Such an enhanced OH* adsorptive behavior favored the capture of OH* species on the Cu 2 O surface, in accord with the CO stripping results (Figure 6g and Figure S20). [47] Since the dissociation of water was a primary step that directly determined the HER activity, we also calculated the adsorption free energies of H 2 O* for the four catalysts (Figure 6h and Figure S21). The values of adsorption energies of ΔG H 2 O * on Ru/CuÀ Cu 2 O@C, CuÀ Cu 2 O@C, Ru/Cu 2 O@C and Ru/Cu@C were À 0.38, À 0.21, À 0.24 and À 0.20 eV, respectively.…”

Metastable Hexagonal-Phase Nickel with Ultralow Pt Content for an Efficient Alkaline/Seawater Hydrogen Evolution Reaction

“…However, once H ads and OH – are adsorbed together, they are likely to recombine into H 2 O at the active site, hindering the production of H 2 . Previously, Fang et al proposed that RuNi shows excellent HER/HOR performance because of more oxophilic sites located on the Ni atoms, which facilitate the adsorption of OH – . A similar two-site mechanism might be fit for our catalyst, − that is, Ni anchors the OH – and leads to accelerated dissociation of water.…”

“…55 proposed that RuNi shows excellent HER/HOR performance because of more oxophilic sites located on the Ni atoms, which facilitate the adsorption of OH − . 56 A similar two-site mechanism might be fit for our catalyst, 57−59 that is, Ni anchors the OH − and leads to accelerated dissociation of water. To confirm this, the results of the CO stripping also investigate the adsorption of OH − on the catalyst.…”

Determination on the Metastable Interface Structure of Nb/MgO(100) Interface

“…[5] In previous simulation works, researchers have referred to the interface structure with the lowest interfacial energy as stable interface structure, while the interface models with higher interfacial energies are termed as metastable interface structures. [6][7][8] Stable interface structure is simple and unique, while metastable interface structures are widely present in composite materials, exhibiting diversity and complexity. [9,10] Therefore, conducting in-depth research on metastable interface structures holds significant importance for the design of interface materials.…”