Constructing Interfacial Oxygen Vacancy and Ruthenium Lewis Acid-Base Pairs to Boost the Alkaline Hydrogen Evolution Reaction Kinetics

Qing Qin; Haeseong Jang; Xiaoli Jiang; Liu Wang; Xuefeng Wang; Min Gyu Kim; Shangguo Liu; Xien Liu; Jaephil Cho

doi:10.1002/anie.202317622

Constructing Interfacial Oxygen Vacancy and Ruthenium Lewis Acid-Base Pairs to Boost the Alkaline Hydrogen Evolution Reaction Kinetics

Angew Chem Int Ed Engl. 2024 Jan 15;63(3):e202317622. doi: 10.1002/anie.202317622. Epub 2023 Dec 15.

Authors

Qing Qin¹, Haeseong Jang², Xiaoli Jiang¹, Liu Wang¹, Xuefeng Wang¹, Min Gyu Kim³, Shangguo Liu¹, Xien Liu¹, Jaephil Cho⁴

Affiliations

¹ College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
² Department of Advanced Materials Engineering, Chung-Ang University, Anseong-si, Gyeonggi-do, 17546, Korea.
³ Beamline Research Division, Pohang Accelerator Laboratory (PAL), Pohang, 37673, South Korea.
⁴ Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea.

PMID: 38061991
DOI: 10.1002/anie.202317622

Abstract

Simultaneous optimization of the energy level of water dissociation, hydrogen and hydroxide desorption is the key to achieving fast kinetics for the alkaline hydrogen evolution reaction (HER). Herein, the well-dispersed Ru clusters on the surface of amorphous/crystalline CeO_2-δ (Ru/ac-CeO_2-δ ) is demonstrated to be an excellent electrocatalyst for significantly boosting the alkaline HER kinetics owing to the presence of unique oxygen vacancy (V_O ) and Ru Lewis acid-base pairs (LABPs). The representative Ru/ac-CeO_2-δ exhibits an outstanding mass activity of 7180 mA mg_Ru ^-1 that is approximately 9 times higher than that of commercial Pt/C at the potential of -0.1 V (V vs RHE) and an extremely low overpotential of 21.2 mV at a geometric current density of 10 mA cm^-2 . Experimental and theoretical studies reveal that the V_O as Lewis acid sites facilitate the adsorption of H₂ O and cleavage of H-OH bonds, meanwhile, the weak Lewis basic Ru clusters favor for the hydrogen desorption. Importantly, the desorption of OH from V_O sites is accelerated via a water-assisted proton exchange pathway, and thus boost the kinetics of alkaline HER. This study sheds new light on the design of high-efficiency electrocatalysts with LABPs for the enhanced alkaline HER.

Keywords: Electrocatalyst; Hydrogen Evolution Reaction; Kinetics; Lewis Acid-Base Pairs; Oxygen Vacancy.

Abstract

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