Turing structuring with multiple nanotwins to engineer efficient and stable catalysts for hydrogen evolution reaction

Low-dimensional nanocrystals with controllable defects or strain modifications are newly emerging active electrocatalysts for hydrogen-energy conversion and utilization; however, a crucial challenge remains in insufficient stability due to spontaneous structural degradation and strain relaxation. Here we report a Turing structuring strategy to activate and stabilize superthin metal nanosheets by incorporating high-density nanotwins. Turing configuration, realized by constrained orientation attachment of nanograins, yields intrinsically stable nanotwin network and straining effects, which synergistically reduce the energy barrier of water dissociation and optimize the hydrogen adsorption free energy for hydrogen evolution reaction. Turing PtNiNb nanocatalyst achieves 23.5 and 3.1 times increase in mass activity and stability index, respectively, compared against commercial 20% Pt/C. The Turing PtNiNb-based anion-exchange-membrane water electrolyser with a low Pt mass loading of 0.05 mg cm-2 demonstrates at least 500 h stability at 1000 mA cm-2, disclosing the stable catalysis. Besides, this new paradigm can be extended to Ir/Pd/Ag-based nanocatalysts, illustrating the universality of Turing-type catalysts. Developing new electrocatalysts for hydrogen production is of high interests. Here the authors report PtNiNb with high-density nanotwins and large strain as hydrogen evolution catalysts in anion-exchange-membrane water electrolyser.

Automated summary

This study presents a Turing structuring strategy that utilizes high-density nanotwins to activate and stabilize ultra-thin metal nanosheets as efficient electrocatalysts for hydrogen evolution reaction. The Turing PtNiNb nanocatalyst exhibits significantly improved mass activity and stability compared to commercial Pt/C, and the stability is also demonstrated in an anion-exchange-membrane water electrolyser.