Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites

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 H SO , delivering a low overpotential of 24 mV at 10 mA cm and a Tafel slope of 38 mV dec . The catalyst exhibits robust stability in a constant current test at a large current density of 162 mA cm 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 H s at 25 mV, and 4.29 H s at 50 mV, in 0.5 m H SO 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 C N , thus considerably facilitating the overall HER performance.

Downshifted d‐Band Center of Ru/MWCNTs by Turbostratic Carbon Nitride for Efficient and Robust Hydrogen Evolution in Alkali

“…Furthermore, they also suffer from a serious metal bleaching in the electrolytes . Recently, the consideration of Ru as a promising candidate or alternatives for HER has been realized through various strategies, which can effectively improve their HER performance in both acidic and basic electrolytes. Anomalous Ru catalysts with new face‐centered cubic (fcc) crystallographic structure deposited on g‐C 3 N 4 /C exhibited 2.5 times higher turnover of frequency (TOF) than the 20 wt % Pt/C in alkaline solutions .…”

Trifunctional Self‐Supporting Cobalt‐Embedded Carbon Nanotube Films for ORR, OER, and HER Triggered by Solid Diffusion from Bulk Metal

“…Moreover, peak between π* and σ* excitations (peak B) was also observed, which is associated with CNC. From the N K‐edge spectra (Figure c), three obvious peaks can be found, which can be ascribed to pyridinic π* (peak A), graphitic π* (peak B) transitions and CNC or CN σ* transition (peak C), respectively . Extended X‐ray absorption fine structure (EXAFS) were carried out to demonstrate the geometry structure of Co/CNFs (1000) sample (Figure d).…”

MoP/Co2P Hybrid Nanostructure Anchored on Carbon Fiber Paper as an Effective Electrocatalyst for Hydrogen Evolution

“…Due to low overpotential, high exchange current density (j 0 ) and fast kinetics, Pt‐based catalysts have been recognized as one of the most active HER catalysts in acidic condition. However, its scarcity in the earth and high cost hampered its large‐scale commercial applications . Hence, seeking for efficient, low‐cost, earth‐abundant and non‐noble metal HER electrocatalysts to replace Pt is of great significance.…”