Stabilizing Hydrous β-NiOOH for Efficient Electrocatalytic Water Oxidation by Integrating Y and Co into Amorphous Ni-Based Nanoparticles

Kevin M Cole; Jehad Abed; Donald W Kirk; Steven J Thorpe

doi:10.1021/acsami.1c18680

Stabilizing Hydrous β-NiOOH for Efficient Electrocatalytic Water Oxidation by Integrating Y and Co into Amorphous Ni-Based Nanoparticles

ACS Appl Mater Interfaces. 2021 Dec 15;13(49):58682-58690. doi: 10.1021/acsami.1c18680. Epub 2021 Dec 3.

Authors

Kevin M Cole¹, Jehad Abed¹, Donald W Kirk², Steven J Thorpe¹

Affiliations

¹ Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S 3E4, Canada.
² Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.

PMID: 34860485
DOI: 10.1021/acsami.1c18680

Abstract

A two-stage ball milling process was used to synthesize amorphous Ni_79.2Nb_12.5Y_8.3 and Ni_74.2Co₅Nb_12.5Y_8.3 nanoparticles from elemental powders. The two-stage ball milling process provides a scalable and industrially applicable method for producing non-metalloid amorphous nanoparticles. The amorphous nanoparticles displayed excellent catalytic performance toward the oxygen evolution reaction (OER) in 1 M KOH, displaying lower overpotentials than IrO₂ at 10 mA cm^-2. The addition of Co in the amorphous alloy reduced the overpotential to 288 mV at 10 mA cm^-2. The pairing of X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy revealed that the improved OER activity of amorphous Ni_74.2Co₅Nb_12.5Y_8.3 was attributed to the catalytic synergy between Y and Co. The integration of Y supported proton-coupled electron-transfer processes that assisted with the electrostatic adsorption of OH^- and formation of oxyhydroxide species, while Co sites enabled metal-oxo bonding to prevent Ni overcharging and the stabilization of β-NiOOH. The catalytic synergy between Y and Co reduces the amount of Co needed to enhance the OER activity of Ni-based alloys and lessens the dependence on Co, which is in high demand in many renewable energy and storage applications.

Keywords: X-ray photoelectron spectroscopy; amorphous alloys; in situ X-ray absorption spectroscopy; nanostructured catalysts; oxygen evolution reaction.