Carbon-Encapsulated WO<sub>x</sub> Hybrids as Efficient Catalysts for Hydrogen Evolution.

Jing, Shengyu; Lu, Jiajia; Yu, Guangtao; Yin, Shibin; Luo, Lin; Zhang, Zengsong; Ma, Yanfeng; Chen, Wei et al. · Adv Mater · 2018

basic_science · Level V

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Abstract

Developing non-noble metal catalysts as Pt substitutes, with good activity and stability, remains a great challenge for cost-effective electrochemical evolution of hydrogen. Herein, carbon-encapsulated WO<sub>x</sub> anchored on a carbon support (WO<sub>x</sub> @C/C) that has remarkable Pt-like catalytic behavior for the hydrogen evolution reaction (HER) is reported. Theoretical calculations reveal that carbon encapsulation improves the conductivity, acting as an electron acceptor/donor, and also modifies the Gibbs free energy of H* values for different adsorption sites (carbon atoms over the W atom, O atom, WO bond, and hollow sites). Experimental results confirm that WO<sub>x</sub> @C/C obtained at 900 °C with 40 wt% metal loading has excellent HER activity regarding its Tafel slope and overpotential at 10 and 60 mA cm<sup>-2</sup> , and also has outstanding stability at -50 mV for 18 h. Overall, the results and facile synthesis method offer an exciting avenue for the design of cost-effective catalysts for scalable hydrogen generation.