Bixbyite-type Ln<sub>2</sub>O<sub>3</sub> as promoters of metallic Ni for alkaline electrocatalytic hydrogen evolution.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35790749.
- Also identified by DOI 10.1038/s41467-022-31561-4 and PMC identifier 9256667.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
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<sub>2</sub>O<sub>3</sub>), which can be implanted into metallic Ni by selective high-temperature reduction to achieve highly efficient Ni/Ln<sub>2</sub>O<sub>3</sub> hybrid electrocatalysts toward hydrogen evolution reaction. The screened Ni/Yb<sub>2</sub>O<sub>3</sub> catalyst shows the low overpotential (20.0 mV at 10 mA cm<sup>-2</sup>), low Tafel slope (44.6 mV dec<sup>-1</sup>), and excellent long-term durability (360 h at 500 mA cm<sup>-2</sup>), significantly outperforming the metallic Ni and benchmark Pt/C catalysts. The remarkable hydrogen evolution activity and stability of Ni/Yb<sub>2</sub>O<sub>3</sub> are attributed to that the Yb<sub>2</sub>O<sub>3</sub> 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.