Ensemble Effect of Ruthenium Single-Atom and Nanoparticle Catalysts for Efficient Hydrogen Evolution in Neutral Media

Abstract

Hydrogen evolution reaction (HER) plays a key role in electrochemical water splitting, which is a sustainable way for hydrogen production. The kinetics of HER is sluggish in neutral media that requires noble metal catalysts to alleviate energy consumption during the HER process. Here, we present a catalyst comprising a ruthenium single atom (Ru1) and nanoparticle (Run) loaded on the nitrogen-doped carbon substrate (Ru1-Run/CN), which exhibits excellent activity and superior durability for neutral HER. Benefiting from the synergistic effect between single atoms and nanoparticles in the Ru1-Run/CN, the catalyst exhibits a very low overpotential down to 32 mV at a current density of 10 mA cm–2 while maintaining excellent stability up to 700 h at a current density of 20 mA cm–2 during the long-term test. Computational calculations reveal that, in the Ru1-Run/CN catalyst, the existence of Ru nanoparticles affects the interactions between Ru single-atom sites and reactants and thus improves the catalytic activity of HER. This work highlights the ensemble effect of electrocatalysts for HER and could shed light on the rational design of efficient catalysts for other multistep electrochemical reactions.

Recent progress and perspective on electrocatalysis in neutral media: Mechanisms, materials, and advanced characterizations

“…They produced a large‐area Pt SACs/CoP nanotube array by depositing nickel foam, which exhibited an extremely low overpotential of 24 mV at j HER = 10 mA cm −2 , comparable with commercial Pt/C (17 mV), but with greater durability than Pt/C. Moreover, Li et al [ 129 ] reported that by introducing dispersed Pt atoms on defect‐rich NiFeMo LDH, the synergistic effect of Mo and single atom Pt and the phase transition into NiFe‐LDH lowers the kinetic energy barrier for the hydrolysis dissociation process and accelerates the HER process under neutral conditions. Overpotentials as low as 37 mV at 10 mA cm −2 were obtained, exceeding the performance of most HER catalysts in neutral media.…”

Atomically Dispersed Ni on Nitrogen‐Doped Carbon Substrate Enhances Basic HER Performance of Ru Clusters**

“…Its position in the volcano diagram is very close to that of Pt and has good HER activity [20,21] . Moreover, Ru costs less than Pt, so using Ru to replace Pt as an efficient HER electrocatalyst is very promising [22,23] . In the alkaline HER, since the H + concentration is very low, the water dissociation step must first be performed [24] .…”

“…[20,21] Moreover, Ru costs less than Pt, so using Ru to replace Pt as an efficient HER electrocatalyst is very promising. [22,23] In the alkaline HER, since the H + concentration is very low, the water dissociation step must first be performed. [24] This results in the reaction rate of basic HER being several orders of magnitude slower than that of acidic HER.…”

Metal–support interactions of 2D carbon-based heterogeneous catalysts for the hydrogen evolution reaction

“…These materials are currently the focus of extensive research for both fundamental studies and practical applications. [30][31][32] With the deepening of research on metal catalytic centers and catalyst carriers, the relationship between them has garnered signicant attention. Metal-support interactions (MSIs), which describe the relationships between metal catalytic centers and supports, determine catalyst performance.…”