Stable Pd-Cu Hydride Catalyst for Efficient Hydrogen Evolution.

Jia, Yanyan; Huang, Tzu-Hsi; Lin, Shuan; Guo, Lisheng; Yu, Yu-Min; Wang, Jeng-Han; Wang, Kuan-Wen; Dai, Sheng · Nano Lett · 2022

basic_science · Level V

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Abstract

Pd has been regarded as one of the alternatives to Pt as a promising hydrogen evolution reaction (HER) catalyst. Strategies including Pd-metal alloys (Pd-M) and Pd hydrides (PdH<sub><i>x</i></sub>) have been proposed to boost HER performances. However, the stability issues, e.g., the dissolution in Pd-M and the hydrogen releasing in PdH<sub><i>x</i></sub>, restrict the industrial application of Pd-based HER catalysts. We here design and synthesize a stable Pd-Cu hydride (PdCu<sub>0.2</sub>H<sub>0.43</sub>) catalyst, combining the advantages of both Pd-M and PdH<sub><i>x</i></sub> structures and improving the HER durability simultaneously. The hydrogen intercalation is realized under atmospheric pressure (1.0 atm) following our synthetic approach that imparts high stability to the Pd-Cu hydride structure. The obtained PdCu<sub>0.2</sub>H<sub>0.43</sub> catalyst exhibits a small overpotential of 28 mV at 10 mA/cm<sup>2</sup>, a low Tafel slope of 23 mV/dec, and excellent HER durability due to its appropriate hydrogen adsorption free energy and alleviated metal dissolution rate.