Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites. Issue 30 (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 international edition. Volume 57:Issue 30(2018)
• Page Start: 9495
• Page End: 9500
• Publication Date: 2018-07-02
• Subjects: carbon-free supports -- hydrogen evolution reaction (HER) -- phosphorus nitride -- ruthenium -- single atoms; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201804854
• Languages: English
• ISSNs: 1433-7851

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. Abstract : The Ru SAs@PN electrocatalyst drives the hydrogen evolution reaction 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 . Amorphous phosphorus nitride imide nanotubes (HPN) stabilize single ruthenium sites with abundant dangling unsaturated phosphorus vacancies. The single atoms (SAs) are anchored by strongly coordinating nitrogen atoms located in the HPN matrix.