Highly Efficient and Selective Photocatalytic CO2 Reduction by Iron and Cobalt Quaterpyridine Complexes

Abstract

Summary

A photochemical reduction of CO₂ to CO was shown using the cobalt complex [Fe(qpy)(H2O)2][ClO4]2 or the iron complex [Co(qpy)(H2O)2][ClO4]2 as catalysts in combination with the ruthenium-based photosensitizer Ru(bpy)3Cl2. Turnover numbers (TONs) up to 2660 and a selectivity of 98% for CO using the cobalt catalyst and TONs of >3000 and a selectivity of 95% for CO using the iron catalyst were reached in acetonitrile/triethanolamine. When swapping the ruthenium photosensitizer for the organic dye sensitizer purpurin, TONs of 790 and 1365 in DMF were obtained for the cobalt and iron catalysts, respectively. The experiments were conducted under visible-light irradiation (λ = 460 nm) using BIH as sacrificial reductants (see section SEDs below).

Content of the published article in detail

The article contains results for the reduction of CO₂ to xx under visible-light catalysis using a xx complex as a catalyst. The catalytic system performs best (referring to the TON of CO production) in xx using xx and xx.

Catalysts

[Fe(qpy)(H2O)2][ClO4]2 [Co(qpy)(H2O)2][ClO4]2 Co(ClO4)2

Photosensitizers

Ru(bpy)3Cl2 purpurin

Investigations

1. REDIRECT Optimizations of conditions for Co(qpy)(H2O)2(ClO4)2 and Ru(bpy)3Cl2

Investigation-Name: Co(qpy)(H2O)2(ClO4)2 and Ru(bpy)3Cl2Export

1. REDIRECT Optimizations of conditions for Fe(qpy)(H2O)2(ClO4)2 and Ru(bpy)3Cl2

Investigation-Name: Fe(qpy)(H2O)2(ClO4)2 and Ru(bpy)3Cl2Export

1. REDIRECT Optimizations of conditions for Co(qpy)(H2O)2(ClO4)2 and purpurin

Investigation-Name: Co(qpy)(H2O)2(ClO4)2 and purpurinExport

1. REDIRECT Optimizations of conditions for Fe(qpy)(H2O)2(ClO4)2

Investigation-Name: Fe(qpy)(H2O)2(ClO4)2Export

Sacrificial electron donor

In this study, the experiments were done with the sacrificial reductant BIH (100508).

Additives

In this study, some experiments were conducted xx