An integrated photocatalytic/enzymatic system for the reduction of CO₂ to methanol in bioglycerol–water

Abstract

SummaryA hybrid enzymatic/photocatalytic approach for the conversion of CO2 into methanol is described. For the approach discussed here, the production of one mol of CH3OH from CO2 requires three enzymes and the consumption of three mol of NADH. Regeneration of the cofactor NADH from NAD+ was achieved by using visible-light-active, heterogeneous, TiO2-based photocatalysts. The efficiency of the regeneration process is enhanced by using a Rh(III)-complex for facilitating the electron and hydride transfer from the H-donor (water or a water–glycerol solution) to NAD+. This resulted in the production of 100 to 1000 mol of CH3OH from one mol of NADH, providing the possibility for practical application.

Direct enzymatic bioelectrocatalysis: differentiating between myth and reality

“…Most commonly, CO 2 reduction has been explored with the aim of producing formate or alkanes/alcohols, although NAD þ reduction to NADH is frequently attempted where NAD-dependent enzymes can support reductive reactions [22][23][24]; Vincent and co-workers [25] have also demonstrated that the coimmobilization of hydrogenase and NAD þ -reducing proteins onto conductive particles can facilitate H 2 -driven NADH production. Recent research has also explored the possibility of reducing dinitrogen (N 2 ) to an important chemical commodity, ammonia (NH 3 ), while simultaneously producing electrical energy [26].…”

Recent Progress and Novel Applications in Enzymatic Conversion of Carbon Dioxide

“…To provide the possibility for practical application, a hybrid enzymatic/photocatalytic approach for efficient converting CO2 into methanol was recently proposed [35]. The proposed approach includes two processes: the enzymatic transformation of CO2 to Scheme 2.…”

Product Selectivity in Homogeneous Artificial Photosynthesis Using [(bpy)Rh(Cp*)X]n+-Based Catalysts

“…It has been shown that under photocatalytic conditions and in the absence of the rhodium catalyst, the formation of complex product mixtures is possible [110]. Steckhan and coworkers identified the reduced nicotinamide cofactor product during photoredox catalysis with [Ru(bpy) 3 ] 2+ as the chromophore in the absence of a rhodium catalyst as the dimeric (NAD) 2 species [73].…”

“…It has been shown that under photocatalytic conditions and in the absence of the rhodium catalyst, the formation of complex product mixtures is possible [110]. Steckhan and coworkers Identically to the photocatalytic generation of hydrogen, the catalytically active rhodium complex is most likely formed via the fast disproportionation of the intermediate Rh II species [33,37].…”

“…A broad variety of photosensitizers have been applied in these systems, ranging from small organic dyes [85,[89][90][91] to functionalized graphenes [92][93][94][95], photoredoxactive polymers [96,97], red light absorbing tin porphyrines from Knör and coworkers [98], ruthenium polypyridine complexes [32,97,99], and different solid photoactive materials [100][101][102][103][104][105][106][107][108][109][110].…”