1. Bixbyite-type Ln 2 O 3 as promoters of metallic Ni for alkaline electrocatalytic hydrogen evolution.
- Author
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Sun H, Yan Z, Tian C, Li C, Feng X, Huang R, Lan Y, Chen J, Li CP, Zhang Z, and Du M
- Abstract
The active-site density, intrinsic activity, and durability of Ni-based catalysts are critical to their application in industrial alkaline water electrolysis. This work develops a kind of promoters, the bixbyite-type lanthanide metal sesquioxides (Ln
2 O3 ), which can be implanted into metallic Ni by selective high-temperature reduction to achieve highly efficient Ni/Ln2 O3 hybrid electrocatalysts toward hydrogen evolution reaction. The screened Ni/Yb2 O3 catalyst shows the low overpotential (20.0 mV at 10 mA cm-2 ), low Tafel slope (44.6 mV dec-1 ), and excellent long-term durability (360 h at 500 mA cm-2 ), significantly outperforming the metallic Ni and benchmark Pt/C catalysts. The remarkable hydrogen evolution activity and stability of Ni/Yb2 O3 are attributed to that the Yb2 O3 promoter with high oxophilicity and thermodynamic stability can greatly enlarge the active-site density, reduce the energy barrier of water dissociation, optimize the free energy of hydrogen adsorption, and avoid the oxidation corrosion of Ni., (© 2022. The Author(s).)- Published
- 2022
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