Bio-Inspired Curvature Engineering across the Periodic Table Tunes Hydrogen Adsorption in Single-Atom Catalysts

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Curvature is a key geometric feature in biological redox centers.
• The catalytic role of curvature in heterogeneous systems is underexplored.
• Single-atom catalysts (SACs) with M N₄ active sites are promising for the hydrogen evolution reaction (HER).

Purpose of the Study:

• To establish curvature engineering as a strategy for modulating M N₄ SAC activity for HER.
• To investigate the relationship between catalyst curvature and electronic structure.
• To identify key descriptors for tuning adsorbate energetics in SACs.

Main Methods:

• Systematic construction of M N₄ SACs with varying curvature (concave, flat, convex) on carbon supports.
• Density functional theory (DFT) calculations to analyze electronic structure and adsorption energies.
• Machine learning (XGBoost) to identify descriptors influencing catalytic activity.

Main Results:

• Each metal (M) in M N₄ SACs exhibits an optimal curvature for HER.
• Curvature-induced electronic relaxation balances metal-hydrogen affinity, achieving near-thermoneutral hydrogen adsorption (ΔG_H*).
• Melting point, curvature, group, and atomic radius were identified as key descriptors for tuning adsorbate energetics.

Conclusions:

• Nanoscale curvature modulation is a generalizable design concept for SACs.
• Curvature acts as a geometrically programmable field influencing electronic structure and catalytic activity.
• Curvature is a predictive and transferable design axis for developing next-generation electrocatalysts.