Carbon dioxide reduction mechanistic studies

Our research focuses on mechanistic and kinetic studies of photochemical and electrochemical CO2 reduction that involves metal complexes as catalysts. This work makes use of UV-vis, NMR, and FTIR spectroscopy, flash photolysis, pulse radiolysis. X-ray diffraction, XANES (X-ray absorption near-edge spectroscopy) and EXAFS (extended X-ray absorption fine structure). Here we summarize our research on photochemical carbon dioxide reduction with metal macrocycles. 

We have initiated investigations intended to characterize homogeneous carbon dioxide reduction processes and our results to date are summarized herein. Specifically, our research centers on mechanistic studies of metal carbonyl anion catalysts, which readily activate CO2 to C-H and C-C bond formation, two of the most important processes in the synthesis of organic materials. 

Photocatalytic reduction of carbon dioxide is an immediate need in the energy as well as environmental points of view. The amount of product formed during the reaction still suffered by lower yield say up to some micromoles. A complete revisit to each individual process associated with the carbon dioxide reduction is required for elucidating the reaction pathways and preparing a suitable mechanism. At this point, the scientist should deviate from the conventional TiCk route [167,172]. The mechanistic studies using TiCk are highly encouraged due... 

Carbon dioxide in AN and DMSO is reduced at around -2 V vs aqueous SCE [45]. Because organic species are sometimes obtained by the electrochemical reduction of C02, mechanistic studies have been carried out in detail by voltammetry. This will be discussed in Section 12.4. 

The electrocatalytic behavior of cathodes appears to play a crucial role in the reduction of carbon dioxide. To find more efficient catalysts, detailed mechanistic studies of CO2 reduction are needed. Further studies could also concentrate on the investigation of different electrolytes as well as different catalysts delivering products of choice, such as alcohols. 

A major focus of more recent studies on adsorption at metal electrodes has been the investigation of the mechanism of electro-oxidation of organic fuels (methanol, formic acid, formaldehyde, etc. [55, 56]) and the electro-reduction of carbon dioxide. The former type of reaction is important in the context of the development of fuel cells a major problem has been the poisoning of the anode by carbon fragments and mechanistic insights are urgently needed. In the latter case, the development of C02 sensors has a high priority. 

Direct excitation of the transition metal complex active in COj reduction was demonstrated in a photosystem composed of tricarbonyl(2,2 -bipyridin-ium)rhenium(I), /ac-Re(bpy)(CO)3X (X = C1, Br) as a light-active compound and a homogeneous catalyst [140-142]. Photosensitized reduction of carbon dioxide to CO proceeds in nonaqueous solutions (i.e., dimethylform-amide) including the rhenium(I) complex and TEOA as the sacrificial electron donor. The quantum efficiency for CO formation in the system corresponds to

Mechanistic studies show that the primary step in... 

DuBois DL, Miedaner A, Haltiwanger RC (1991) Electrochemieal reduction of carbon dioxide catalyzed by [Pd(triphosphine)(solvent)](BF4)2 cmnplexes synthetic and mechanistic studies. J Am Chem Soc 113(23) 8753-8764. doi 10.1021/ja00023a023... 

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