Metal-free reduction of CO2 to formate using a photochemical organohydride-catalyst recycling strategy

Abstract

Summary

A photochemical reduction of CO₂ to CO was shown using -missing link parameter- as catalyst in combination with the organic carbazole-based photosensitizer 3,6-bis(dimethylamino)-9-phenyl-9H-carbazole. Turnover numbers (TONs) of 6080 for the catalyst and 8820 for the photosensitizer and an exclusive selectivity for formic acid were reached in MeCN/H₂O with catalyst xx. The experiments were conducted under visible-light irradiation (λ = 400 nm) using ascorbic acid as sacrificial electron donor (see section SEDs below).

Content of the published article in detail

The article contains results for the reduction of CO₂ to HCOO^- under visible-light catalysis using as a catalyst. The catalytic system performs best (referring to the TON of formic acid production) in MeCN/H₂O.

Catalyst

1,2,3-Trimethylbenzimidazolium iodide

Photosensitizer

3,6-bis(dimethylamino)-9-phenyl-9H-carbazole

Sacrificial electron donor

In this study, the experiments were done with the sacrificial electron donor ascorbic acid L-ascorbate, sodium. The use of BIH was tested, but found to yield worse results.

Additives

In this study, potassium carbonate was added as a base.