Ce Single Atom-Engineered Amorphous/Crystalline Nanosheets for Enhanced Alkaline Water Electrolysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient hydrogen evolution reaction (HER) is crucial for green hydrogen production via water electrolysis.
• Achieving industrial current densities requires nanocatalysts with fast water dissociation kinetics.
• Current catalysts face challenges in meeting these demands.

Purpose of the Study:

• To design and synthesize a novel single-atom engineered nanocatalyst for enhanced alkaline HER.
• To investigate the catalytic performance and mechanism of the new material.
• To demonstrate its potential in anion exchange-membrane water electrolyzers (AEMWEs).

Main Methods:

• Single-atom engineering to create cerium-doped amorphous RuOx nanosheets (ac-CeSA Rux) with amorphous/crystalline nanojunctions.
• Electrochemical characterization of HER performance, including overpotential and Tafel slope.
• Anion exchange-membrane water electrolyzer (AEMWE) testing.
• In situ spectroscopic analyses and density functional theory (DFT) calculations.

Main Results:

• The ac-CeSA Rux catalyst exhibited an exceptionally low overpotential (8.3 mV at 10 mA cm-2) and Tafel slope (23.1 mV dec-1).
• AEMWE tests showed a low cell voltage (1.71 V at 1000 mA cm-2) with stable performance over 300 hours.
• In situ spectroscopy confirmed enhanced water dissociation due to increased OH species coverage.
• DFT calculations revealed reduced water dissociation energy barriers and optimized H* adsorption.

Conclusions:

• The developed ac-CeSA Rux catalyst significantly boosts alkaline HER performance.
• The amorphous/nanocrystalline nanojunctions and single-atom doping are key to enhanced water dissociation and HER kinetics.
• This work presents a promising strategy for designing advanced nanocatalysts for efficient electrocatalysis and green hydrogen production.