Identification and manipulation of dynamic active site deficiency-induced competing reactions in electrocatalytic oxidation processes

DOI: 10.1039/D1EE03522C

Authors: Runjia Lin (University College London) , Liqun Kang (University College London) , Tianqi Zhao (University College London) , Jianrui Feng (Nankai University) , Veronica Celorrio (Diamond Light Source) , Guohui Zhang (Imperial College London) , Giannantonio Cibin (Diamond Light Source) , Anthony Kucernak (Imperial College London) , Dan Brett (University College London) , Furio Cora (University College London) , Ivan P. Parkin (University College London) , Guanjie He (University College London; University of Lincoln)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Energy & Environmental Science

State: Published (Approved)
Published: March 2022
Diamond Proposal Number(s): 25410 , 29207

Abstract: Electrocatalytic organic compound oxidation reactions (OCORs) have been intensively studied for energy and environmentally benign applications. However, relatively little effort has been devoted to developing a fundamental understanding of OCOR, including the detailed competition with side reactions and activity limitations, thus inhibiting the rational design of high-performance electrocatalysts. Herein, by taking NiWO4-catalysed urea oxidation reaction (UOR) in aqueous media as an example, the competition between the OCOR and the oxygen evolution reaction (OER) within a wide potential range is examined. It is shown that the root of the competition can be ascribed to insufficient surface concentration of dynamic Ni3+, an active site shared by both UOR and OER. Similar phenomenon are observed in other OCOR electrocatalysts and systems. To address the issue, a “controllable reconstruction of pseudo-crystalline bimetal oxides” design strategy is proposed to maximise the dynamic Ni3+ population and manipulate the competition between UOR and OER. The optimised electrocatalyst delivers best-in-class performance and a ~10-fold increase in current density at 1.6 V versus the reversible hydrogen electrode for alkaline urea electrolysis compared to that of the pristine materials.

Subject Areas: Chemistry, Energy, Environment

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: B18-Core EXAFS , E01-JEM ARM 200CF , E02-JEM ARM 300CF

Added On: 30/03/2022 10:27

Documents:
d1ee03522c.pdf

Discipline Tags:

Energy Storage Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Catalysis Chemistry

Technical Tags:

Microscopy Spectroscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM) X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS) X-ray Absorption Near Edge Structure (XANES) Scanning Transmission Electron Microscopy (STEM)