Functionalized Embedded Monometallic Nickel Catalysts for Enhanced Hydrogen Evolution: Performance and Stability. Issue 8 (4th August 2021)

• Record Type: Journal Article
• Authors: Doan, Huong; Kendrick, Ian; Blanchard, Remi; Jia, Qingying; Knecht, Ellie; Freeman, Andrew; Jankins, Tanner; Bates, Michael K.; Mukerjee, Sanjeev
• Is Part Of: Journal of the Electrochemical Society. Volume 168:Issue 8(2021)
• Publication Date: 2021-08-04
• Subjects: Hydrogen evolution reaction -- Electrocatalysis -- Anion Exchange Membrane -- Electrolyzer -- Hydrogen Generation; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac11a1
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Viable anionic exchange membrane (AEM) electrolysis for H2 production requires highly active hydrogen evolution reaction (HER) catalysts that are also robust and cost-effective. Traditionally juxtaposition of two transition metals with one being more oxophilic is necessary for easier access to water in the inner Helmholtz plane as a source of protons in the crucial Volmer step for enhanced HER activity. However, they are prone to passivation at anodic potentials or deactivation via the formation of sub-surface metal hydrides at high cathodic overpotentials. Here we report a method of enabling close juxtaposition of Ni-Ni-oxide surfaces by functionalizing Ni-based catalysts via the careful thermal treatment of carbon-supported Ni nano-particles chelated with a select organic chelating compound referred to as cupferron. This functionalization results in an embedded Ni surface with a clear graphitic coating engendering long-term stability for passivation and subsurface hydride formation. The stability and activity of the functionalized Ni catalyst are demonstrated in half-cell RDE and full-cell AEM membrane-based hydrogen pump experiments. In the case of the latter, the functionalized Ni outperforms carbon-supported Pt.