New catalyst design could cut the cost of green hydrogen production
Scientists have identified how to engineer a rare material called tantalum oxynitride to dramatically improve its ability to generate hydrogen from water—a key step in producing clean fuel at scale. By applying mechanical strain to specific crystal surfaces, researchers showed they can boost the material's catalytic efficiency, potentially making green hydrogen cheaper to produce commercially.
Originaltitel: Strain-Modulated Tuning of Rashba Signature and Catalytic Activity on Oxynitride Surface: Facet Matters
Tantalum-based oxynitride perovskite SrTaO2N distinguishes itself as a rare semiconducting material, exhibiting remarkable stability in aqueous environments and a narrow band gap, rendering it a highly active catalyst for the hydrogen evolution reaction (HER). In this study, we employ first-principles density functional theory (DFT) calculations to provide mechanistic insights into the electrochemical HER occurring on the low-indexed (001) and (110) surfaces. The computed adsorption free energy of hydrogen adsorption (ΔGH) for these facets indicates their favorable catalytic activity toward HER. Additionally, a detailed analysis of the system’s electronic structure reveals the elemental contribution to both the valence and conduction band edges. The influence of the biaxial strain on enhancing the selectivity of the oxynitride system for hydrogen evolution is also thoroughly examined. Finally, the strain-modulated HER activity is elucidated through changes in the charge profile, providing a deeper understanding of the strain-induced effects on surface charge contribution and catalytic performance.