Rational Design of an Iridium-Tungsten Composite with an Iridium-Rich Surface for Acidic Water Oxidation

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Jiajian Gao
  • Xiang Huang
  • Weizheng Cai
  • Qilun Wang
  • Chunmiao Jia

Detail(s)

Original languageEnglish
Pages (from-to)25991-26001
Journal / PublicationACS Applied Materials and Interfaces
Volume12
Issue number23
Online published19 May 2020
Publication statusPublished - 10 Jun 2020
Externally publishedYes

Abstract

Developing highly active and stable water oxidation catalysts with reduced cost in acidic media plays a critical role in clean energy technologies such as fuel cells and electrolyzers. Precious iridium-based oxides are still the only oxygen evolution reaction (OER) catalysts with reasonable activity and stability in acid. Herein, we design iridium-tungsten composites with a metallic tungsten-rich core and an iridium-rich surface by the sol-gel method followed by hydrogen reduction. The thus obtained iridium-tungsten catalyst shows much higher intrinsic water oxidation activity (100 mA/mgIr at an overpotential of 290 mV) and stability (100 h at 10 mA/cm2geom) together with reduced iridium content (33 wt % only) as compared with pure iridium oxide. An operando method using H2O2 as a probe molecule is developed to determine the relative adsorption strength of the reaction intermediates (*OH and *OOH) in the OER process. Detailed characterization shows that the tungsten-incorporated surface not only modulates the adsorption energy of oxygen intermediates on iridium but also enhances the stability of iridium species in acid, while the metallic tungsten core exhibits high electrical conductivity, all of which collectively give rise to the much enhanced catalytic performance of iridium-tungsten composite in acidic water oxidation. A single-membrane electrode assembly is further prepared to demonstrate the advantages and potential application of iridium-tungsten composite in practical proton exchange membrane electrolyzers. © 2020 American Chemical Society.

Research Area(s)

  • acidic water oxidation, catalyst design, core-shell structure, electrocatalysis, oxygen evolution reaction

Citation Format(s)

Rational Design of an Iridium-Tungsten Composite with an Iridium-Rich Surface for Acidic Water Oxidation. / Gao, Jiajian; Huang, Xiang; Cai, Weizheng et al.
In: ACS Applied Materials and Interfaces, Vol. 12, No. 23, 10.06.2020, p. 25991-26001.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review