Light-driven carbon dioxide reduction coupled with conversion of acetylenic group to ketone by a functional Janus catalyst based on keplerate {Mo₁₃₂}

Abstract

A novel dual functional Janus catalyst {Mo132} for photocatalytic carbon dioxide reduction coupled with organic hydroxylation from phenylacetylene to acetophenone is reported.

Carbonic Anhydrase-Mimicking Keplerate Cluster Encapsulated Iron Trimesate for Base-Free CO2 Hydrogenation

“…The symmetric A g -type breathing vibration of μ 3 -O atoms in pentagonal [Mo VI 6 ] moieties (875 cm –1 ) and the asymmetric stretching vibration of MoO t (O t = terminal oxygen) bonds (952 cm –1 ) were also observed in x % Mo 132 @MIL-100­(Fe) materials as weak bands (Figure b, arrows), whereas no such peaks were observed in MIL-100­(Fe). Another strong peak indicating the bending vibration of MoO t bonds (369 cm –1 ) was not observed in x % Mo 132 @MIL-100­(Fe) materials . Although the FTIR spectra indicated ligand groups (water, acetate, and ammonium ions) associated with the Mo 132 cluster in the 1350–1650 cm –1 range (Figure c), they were merged with carboxylate groups of MIL-100­(Fe), which made their presence in the x % Mo 132 @MIL-100­(Fe) structures impossible to verify.…”

Fabrication of Soft-Oxometalates {Mo132} Clusters With Novel Azobenzene Surfactants: Size Control by Micelles and Light

“…After UV illumination for a certain time, the CV curve of pure {Mo 132 } showed a significant decrease in the current intensity after light exposure, and the oxidation potential was shifted to right from −0.45 V to −0.2 V ( Figure 6C ), which may be due to the photosensitivity of {Mo 132 } ( Lodh et al, 2018 ). UV light induced unstable dissociation of part of {Mo 132 }, leading to a decrease in the total concentration of {Mo 132 } in solution and a decrease in the current intensity.…”

En route to artificial photosynthesis: the role of polyoxometalate based photocatalysts

“…The employment of a Janus catalyst, i.e., a dual functional catalyst 190,191 based on Mo 132 clusters, reduces CO 2 to HCOOH, and the consecutive water oxidation is coupled with hydration of acetylenic bonds (phenylacetylene) to synthesize a ketone (acetophenone). 192 The mixed valent Mo V /Mo VI centres act as the redox centres of the catalyst, and such abundance of the mixed-valent centres (Mo V /Mo VI ¼ 0.83) accounts for the catalyst's efficiency. Surprisingly, an increase in the number of such reduced metal centres (Mo V /Mo VI ¼ 3) results in the generation of more reduced products like HCHO.…”