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Photo‐Assisted Electrocatalytic Reduction of CO 2 : A New Strategy for Reducing Catalytic Overpotentials
Author(s) -
Taylor James O.,
Wang Yibo,
Hartl František
Publication year - 2020
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201901887
Subject(s) - overpotential , catalysis , chemistry , electrochemistry , bipyridine , photochemistry , electrocatalyst , reactivity (psychology) , 2,2' bipyridine , redox , inorganic chemistry , electrode , organic chemistry , medicine , alternative medicine , crystal structure , pathology
Electrochemical and photochemical reduction of CO 2 are both well‐established, independent catalytic routes toward producing added‐value chemicals. The potential for any cross‐reactivity has, however, hardly been explored so far. In this report, we assess a system primarily using spectroelectrochemical monitoring, where photochemistry assists the cathodic activation of precursor complexes fac ‐[Mn(CO) 3 (2,2′‐bipyridine)Br] and [Mo(CO) 4 (6,6′‐dimethyl‐2,2′‐bipyridine)] to lower the catalytic overpotential needed to trigger the electrocatalytic reduction of CO 2 to CO. Following the complete initial 1e − reduction of the parent complexes, the key photochemical cleavage of the Mn−Mn and Mo−CO bonds in the reduction products, [Mn(CO) 3 (2,2′‐bipyridine)] 2 and [Mo(CO) 4 (6,6′‐dimethyl‐2,2′‐bipyridine)] .− , respectively, generates the 2e − ‐reduced, 5‐coordinate catalysts, [Mn(CO) 3 (2,2′‐bipyridine)] − and [Mo(CO) 3 (6,6′‐dimethyl‐2,2′‐bipyridine)] 2− appreciably closer to the initial cathodic wave R1. Experiments under CO 2 confirm the activity of both electrocatalysts under the photoirradiation with 405 nm and 365 nm light, respectively. This remarkable achievement corresponds to a ca. 500 mV positive shift of the catalytic onset compared to the exclusive standard electrocatalytic activation.