Stabilizing Low‐Valence Single Atoms by Constructing Metalloid Tungsten Carbide Supports for Efficient Hydrogen Oxidation and Evolution

Abstract

Designing novel single‐atom catalysts (SACs) supports to modulate the electronic structure is crucial to optimize the catalytic activity, but rather challenging. Herein, a general strategy is proposed to utilize the metalloid properties of supports to trap and stabilize single‐atoms with low‐valence states. A series of single‐atoms supported on the surface of tungsten carbide (M‐WCx, M=Ru, Ir, Pd) are rationally developed through a facile pyrolysis method. Benefiting from the metalloid properties of WCx, the single‐atoms exhibit weak coordination with surface W and C atoms, resulting in the formation of low‐valence active centers similar to metals. The unique metal‐metal interaction effectively stabilizes the low‐valence single atoms on the WCx surface and improves the electronic orbital energy level distribution of the active sites. As expected, the representative Ru‐WCx exhibits superior mass activities of 7.84 and 62.52 A mgRu‐1 for the hydrogen oxidation and evolution reactions (HOR/HER), respectively. In‐depth mechanistic analysis demonstrates that an ideal dual‐sites cooperative mechanism achieves a suitable adsorption balance of Had and OHad, resulting in an energetically favorable Vollmer step. This work offers new guidance for the precise construction of highly active SACs.

Optimizing Electronic Density at Active W Sites for Boosting Photocatalytic H2 Evolution

“…In the end, it was be calcinated under Ar at 900 °C for 2 h with a heating rate of 5 °C min −1 . 20 2.4. Synthesis of W−WC−W 2 C/CdS, WC/CdS, W 2 C/CdS, and WC−W 2 C/CdS Composites.…”

“…The synthesis of WC-W 2 C begins by adding 700 mg NaWO 4 and 474 mg dopamine hydrochloride to 50 mL deionized water, then adding 1 mL hydrochloric acid solution (2M) and stirring for 2 h. The Yellow solid was collected and washed three times with deionized water and then obtained after drying for 12 h in a 70 °C vacuum oven. In the end, it was be calcinated under Ar at 900 °C for 2 h with a heating rate of 5 °C min –1 …”

Ultrastable and highly efficient hydrogen evolution by heterogeneous NiO/Ni catalysts under industrial electrolysis conditions

“…6–8 Although platinum-based catalysts perform well in the hydrogen evolution reaction (HER), their low Earth abundance and high cost restrict their application in industrial-scale hydrogen production. 9–12 In this context, research has been focused on developing inexpensive and abundantly available HER catalysts, including transition-metal-based oxides (hydroxides), 13–15 phosphides, 16–19 carbides, 20–23 nitrides 24–26 and metal alloys. 27–29 Despite significant efforts made in the field of non-precious metal HER catalysts, few of these reported electrocatalysts possess both high catalytic activity and stability under industrial conditions (50–90 °C, 3–6 M KOH).…”

Electrocatalytic Hydrogen Production and Synergistic Formaldehyde Degradation

“…However, these methods release large amounts of CO 2 (∼300 MT), which pose severe environmental problems. , Water splitting, on the other hand, is a clean and ecofriendly method for hydrogen production because of its absence of CO 2 emission. Up to now, various catalysts for hydrogen production have been developed, including transition metal oxides, − MXene-based catalysts, , single-atom catalysts, and other catalyst materials. However, hydrogen production via water splitting still remains a significant challenge due to the sluggish oxygen evolution reaction (OER) kinetics, which necessitates the use of a high overpotential, − As a result, water electrolysis technology is highly energy-intensive, which greatly restricts its industrial-scale application.…”