H₃O⁺ assisted hydrogen spillover over Ru-Mo₂Ti₂C₃ for efficient alkaline hydrogen evolution

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The alkaline hydrogen evolution reaction (HER) is limited by low H* supply and high transport barriers.
• Existing catalysts struggle with efficiency in alkaline media.

Purpose of the Study:

• To develop a novel electrocatalyst for efficient HER in alkaline environments.
• To investigate a strategy for enhancing H* kinetics via H3O+ formation and transport.

Main Methods:

• Synthesis of Ru nanoclusters supported by 2D Mo2Ti2C3 nanosheets (Ru-Mo2Ti2C3).
• Electrochemical characterization of Ru-Mo2Ti2C3 for HER performance in alkaline media.
• Analysis of H* generation, H3O+ formation, and diffusion mechanisms.

Main Results:

• Ru-Mo2Ti2C3 demonstrates efficient water dissociation and rapid H* generation.
• Formation of H3O+ facilitates faster H* transfer to MXene active sites.
• Achieved an overpotential of 47 mV at 10 mA cm-2 in alkaline media, outperforming acidic conditions (108 mV).

Conclusions:

• The Ru-Mo2Ti2C3 catalyst effectively overcomes limitations of alkaline HER through synergistic catalysis.
• This approach offers a new strategy for developing pH-universal and efficient electrocatalysts for H2 evolution.