Auto-optimizing Hydrogen Evolution Catalytic Activity of ReS₂ through Intrinsic Charge Engineering

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Optimizing catalyst electronic states is crucial for high activity, as thermodynamics alone may not suffice.
• Monolayer transition metal dichalcogenides (TMDs) are promising electrocatalysts, but their activity needs enhancement.

Purpose of the Study:

• To investigate the impact of intrinsic charge engineering on the catalytic activity of ReS2 for the hydrogen evolution reaction (HER).
• To demonstrate an auto-optimizing effect on active electronic states for superior catalytic performance.

Main Methods:

• Experimental and theoretical investigations of monolayer ReS2.
• Analysis of charge compensation mechanisms and their effect on electronic states.
• Measurement of hydrogen adsorption free energies (ΔGH*) and electrochemical performance.

Main Results:

• Intrinsic charge compensation between S and Re-Re bonds in ReS2 modulates active electronic states.
• Two S sites showed optimal hydrogen adsorption free energies (0.016 and 0.061 eV), close to the ideal value.
• ReS2 exhibited high turnover frequency (1-10 s⁻¹) and low overpotential (-147 mV at 10 mA cm⁻²).

Conclusions:

• Intrinsic charge engineering provides an auto-optimizing strategy for designing highly active catalysts.
• This approach enhances HER activity by achieving optimal hydrogen binding on active sites.
• The findings open new avenues for designing advanced catalysts through charge engineering.