Engineering Vacancy‐Atom Ensembles to Boost Catalytic Activity toward Hydrogen Evolution
Ruofan Shen, Yanyan Liu, Hao Wen, Xianli Wu, Zhikun Peng, Sehrish Mehdi, Tao Liu, Huanhuan Zhang, Shuyan Guan, Erjun Liang, Baojun Li
Abstract
The dissociation of water is the rate‐determining step of several energy‐relating reactions due to high energy barrier in homolysis of H‐O bond. Herein, engineering vacancy‐atom ensembles via injecting oxygen vacancy (V O ) into single facet‐exposed TiO 2 ‐Pd catalyst to form V O ‐Pd ensemble is proposed and implemented. The outstanding activity of as‐prepared catalyst, 1.5‐PdTV O , toward water dissociation is established with a turnover frequency of 240 min −1 in ammonia borane hydrolysis at 298 K. Density functional theory simulation suggests that the V O ‐Pd ensemble is responsible for the high intrinsic catalytic activity. Water molecules tend to be dissociated on V O sites and ammonia borane molecules on Pd atoms. Those H atoms from water dissociation on V O combine with H atoms from ammonia borane on Pd atoms to generate H 2 . This insights into engineering vacancy‐atom ensembles catalysis provide a new avenue to design catalytic materials for important energy chemical reactions.