CO2 Photoreduction

Whereas formato complexes generally produce formate, metal carboxylates (or metal CO2 adducts) generally lead to CO production [5]. Hawecker et al. [56] concluded that the Re(bpy)(C0)3(02CH) is a side-product and an unlikely intermediate in the photochemical CO production. Re(bpy)(C0)3(02CH) is only half as active as a CO2 photoreduction catalysts than Re(bpy)(CO)3(Cl). Re(bpy)(C0)3(02CH) production is suppressed in the presence of excess Cl whereas in the absence of excess CC ion Re(bpy)(C0)3(02CH) accumulates. Further, Re(bpy)(CO)3(02CH) is also formed as a side-product in the electrochemical reduction [61]. 

Metal sulfides such as ZnS, CdS, and Cd Zni+ S can work as CO2 photoreduction catalysts in the presence of a sacrificial electron dmior [119,124,125,127, 128, 151]. Although the reaction products of CO2 are formic acid and CO in dry conditions, H2 is also generated in the presence of H2O. The quantum yields of CO2... 

In the artificial photosynthesis instead of producing NADPH, the final product is methanol. Although CO2 photoreduction has similar photochemical fundamentals to hydrogen production from water (eq.3), methanol production (eq.4) is a much more complicated and difficult process because of the nature of 6-electron reaction compared to the 2-electron reaction of hydrogen production. 

The two equations above illustrates that the reduction of CO2 to methanol is a scientifically severe challenge. Inoue et al. (Inoue et al., 1979) [5] were the first to report CO2 photoreduction to methanol in 1979 over binary inorganic materials with a... 

For the photocatalytic reduction of CO2, in 1979, Inoue et al. introduced a slurry reactor in which catalysts were suspended in water [143]. Until 2000, slurry-type reactors were widely considered for reduction of CO2 under UV or visible irradiation. On the other hand, Tahir and Amin suggested that this type of reactor is not efficient for enhancing the photocatalytic activity due to the low surface area and complicated separation process required to isolate the miniature catalyst grains [144]. Furthermore, one of the UmitatirHis for CO2 photoreduction in the liquid phase is due to its low solubility in water. Therefore, Rossetti et al. developed an innovative cmicept of photoreactor, allowing to operate under high pressure (up to... 

Batch annular reactor Suspended 9 W Hg lamp CO2 photoreduction [169]... 

Lee W-H, Liao C-H, Tsai M-F, Huang C-W, Wu JC (2013) A novel twin reactor for CO2 photoreduction to mimic artificial photosynthesis. Appl Catal Environ 132 445—451... 

Liu L, Gao F, Zhao H, Li Y (2013) Tailoring Cu valtaice and oxygen vacancy in Cu/Ti02 catalysts for enhanced CO2 photoreduction efficiency. Appl Catal Environ 134 349-358... 

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