Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites. (2nd July 2018)

• Record Type: Journal Article
• Authors: Yang, Jian; Chen, Bingxu; Liu, Xiaokang; Liu, Wei; Li, Zhijun; Dong, Juncai; Chen, Wenxing; Yan, Wensheng; Yao, Tao; Duan, Xuezhi; Wu, Yuen; Li, Yadong
• Is Part Of: Angewandte Chemie. Volume 130:Number 30(2018)
• Page Start: 9639
• Page End: 9644
• Publication Date: 2018-07-02
• Subjects: Einzelatomstrukturen -- Kohlenstofffreie Träger -- Phosphornitrid -- Ruthenium -- Wasserstoffentwicklung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201804854
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Amorphous phosphorus nitride imide nanotubes (HPN) are reported as a novel substrate to stabilize materials containing single‐metal sites. Abundant dangling unsaturated P vacancies play a role in stabilization. Ruthenium single atoms (SAs) are successfully anchored by strong coordination interactions between the d orbitals of Ru and the lone pair electrons of N located in the HPN matrix. The atomic dispersion of Ru atoms can be distinguished by X‐ray absorption fine structure measurements and spherical aberration correction electron microscopy. Importantly, Ru SAs@PN is an excellent electrocatalyst for the hydrogen evolution reaction (HER) in 0.5 m H2 SO4, delivering a low overpotential of 24 mV at 10 mA cm −2 and a Tafel slope of 38 mV dec −1 . The catalyst exhibits robust stability in a constant current test at a large current density of 162 mA cm −2 for more than 24 hours, and is operative for 5000 cycles in a cyclic voltammetry test. Additionally, Ru SAs@PN presents a turnover frequency (TOF) of 1.67 H2 s −1 at 25 mV, and 4.29 H2 s −1 at 50 mV, in 0.5 m H2 SO4 solution, outperforming most of the reported hydrogen evolution catalysts. Density functional theory (DFT) calculations further demonstrate that the Gibbs free energy of adsorbed H* over the Ru SAs on PN is much closer to zero compared with the Ru/C and Ru SAs supported on carbon and C3 N4, thus considerably facilitating the overall HER performance.