Bixbyite-type Ln2O3 as promoters of metallic Ni for alkaline electrocatalytic hydrogen evolution

• Published in: Nature communications Vol. 13; no. 1; pp. 3857 - 13
• Main Authors: Sun, Hongming, Yan, Zhenhua, Tian, Caiying, Li, Cha, Feng, Xin, Huang, Rong, Lan, Yinghui, Chen, Jing, Li, Cheng-Peng, Zhang, Zhihong, Du, Miao
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.07.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/146; 147/135; 147/143; 639/301/299/886; 639/4077/909/4086; 639/638/161/886; Alkaline water; Catalysts; Density; Durability; Electrocatalysts; Electrolysis; Energy of dissociation; Evolution; Free energy; High temperature; Humanities and Social Sciences; Hydrogen; Hydrogen evolution reactions; Hydrogen-based energy; Industrial applications; Metals; multidisciplinary; Noble metals; Oxidation; Promoters; Science; Science (multidisciplinary); Sesquioxides; Stability
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-31561-4

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 O 3 ), which can be implanted into metallic Ni by selective high-temperature reduction to achieve highly efficient Ni/Ln 2 O 3 hybrid electrocatalysts toward hydrogen evolution reaction. The screened Ni/Yb 2 O 3 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/Yb 2 O 3 are attributed to that the Yb 2 O 3 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. While renewable H 2 evolution will require inexpensive, abundant catalysts, non-noble metals typically show relatively low activities. Here, authors examine lanthanide metal sesquioxide doped metallic Ni and show efficient, stable performances for alkaline H 2 evolution electrocatalysis.