Selective visible light reduction of carbon dioxide over iridium(III)-terpyridine photocatalysts

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Chang-ting Wang
  • Jiayuan Xu
  • Fangfang Wei
  • Chi Yung Yam
  • Keith Man-Chung Wong

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number100563
Journal / PublicationMaterials Today Chemistry
Volume22
Online published22 Sept 2021
Publication statusPublished - Dec 2021

Abstract

The CO2 reduction reaction is an imperative piece of technology that closes the carbon cycle in many critical energy conversion and chemical manufacturing processes. Here, we report two new iridium (III) terpyridine-based photocatalysts capable of selective reduction of CO2 to CO under visible light (λ >= 420 nm). The first photocatalyst, [Ir-COOH], was functionalized with the carboxyl group on the phenylpyridine, whereas the second, [Ir-PhCOOH], was attached to a phenyl spacer on the terpyridine. The [Ir-PhCOOH] was characterized by a higher extinction coefficient than [Ir-COOH], thus allowing more absorption of photons. Although both photocatalysts require two-electron activation, the [Ir-PhCOOH] is more readily activated as a result of the more negatively charged Ir center. These photo catalysts show exclusive selectivities in the production of CO. The turnover frequencies for [Ir-COOH] and [Ir-PhCOOH] were 19 and 10 h-1, respectively, under visible light irradiation. The e-e-H-H pathway was identified as the most favorable, consisting of the rate-limiting step in the conversion of *COOH to *CO, and where the barrier is significantly lower for [Ir-PhCOOH] than for [Ir-COOH]. (C) 2021 Elsevier Ltd. All rights reserved.

Research Area(s)

  • CO2, Photocatalyst, Iridium, Visible light, Mechanism, ELECTROCHEMICAL REDUCTION, PHOTOCHEMICAL REDUCTION, RHENIUM(I) COMPLEXES, ELECTRON-TRANSFER, AB-INITIO, EFFICIENT, ACETONITRILE, MACROCYCLES, COBALOXIME

Citation Format(s)

Selective visible light reduction of carbon dioxide over iridium(III)-terpyridine photocatalysts. / Wang, Chang-ting; Chen, Jinfan; Xu, Jiayuan et al.
In: Materials Today Chemistry, Vol. 22, 100563, 12.2021.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review