Boosting hydrogen evolution activity in alkaline media with dispersed ruthenium clusters in NiCo-layered double hydroxide

• Published in: Electrochemistry communications 2019-04, Vol.101, p.23-27
• Main Authors: Li, Dan, Zhang, Bowei, Li, Yang, Chen, Rongsheng, Hu, Shan, Ni, Hongwei
• Format: Article
• Language: English
• Subjects: Hydrogen evolution reaction; NiCo-layered double hydroxide; Ruthenium; Water dissociation
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2019.01.014

Herein, we report a hybrid electrocatalyst consisting of Ru clusters trapped in NiCo-layered double hydroxide (NiCo-LDH) as the basis for an efficient hydrogen evolution reaction (HER) in alkaline media. Benefiting from the fast water dissociation kinetics on NiCo-LDH and favorable H recombination on Ru, the resultant Ru-NiCo-LDH shows an extremely low HER overpotential of 28 mV at a current density of 10 mA cm−2 with a small Tafel slope of 42 mV dec−1. This superior catalytic activity can be ascribed to its high charge transfer ability and to the synergistic effect of the highly dispersed Ru and the NiCo-LDH. Moreover, we also found that the oxidized Ru incorporated in NiCo-LDH was entirely reduced to Ru0 under hydrogen-evolution conditions, which suggests that Ru0 is the true catalytically active phase responsible for the outstanding HER performance. •A Ru-NiCo-LDH catalyst was developed and exhibited very high HER activity of 28 mV at 10 mA cm−2.•The hybrid catalyst with rational design is proven to be effective toward HER in alkaline media.•The incorporated Ru species can be reduced into Ru0 during HER progress.