Light driven styrene epoxidation and hydrogen generation using H₂O as an oxygen source in a photoelectrosynthesis cell

Abstract

This proof-of-concept dye-sensitized photoelectrosynthesis cell is able to produce a high-value chemical by the epoxidation of an alkene in water using sunlight and, at the same time, produce a solar fuel such as hydrogen.

Photocatalytic Asymmetric Epoxidation of Terminal Olefins Using Water as an Oxygen Source in the Presence of a Mononuclear Non-Heme Chiral Manganese Complex

“…Thus, the nature of the asymmetric epoxidizing intermediate(s) (e.g., Mn­(V)–oxo, Mn­(IV)–oxo, or Mn–OX (X = OH or OR)) remains to be clarified . In addition, although the formation of a non-heme Mn­(IV)–oxo complex (and non-heme Fe­(IV)–oxo and Ru­(IV)–oxo complexes) under photocatalytic oxidation conditions has been demonstrated recently, − a detailed mechanism of the photoinduced generation of the M­(IV)–oxo complex has yet to be addressed.…”

Determining the Fate of a Non-Heme Iron Oxidation Catalyst Under Illumination, Oxygen, and Acid

“…Because of their distinct advantages, many researchers have tried to get the best of both worlds by anchoring molecular catalysts to metal oxides to improve the water oxidation efficiency while also eliminating the need for a sacrificial reagent such as Ce IV . − These molecular/solid-state architectures show higher efficiencies toward the OER under both acidic and neutral conditions, but with lifetimes of only a few hours for most cases. Here, cues are taken from the many examples of anchoring molecular dyes and organic oxidation catalysts to semiconductor surfaces for dye-sensitized solar cells (DSSCs) − and photoelectrosynthetic (PES) cells. − …”

Enhanced Photostability of a Ruthenium(II) Polypyridyl Complex under Highly Oxidizing Aqueous Conditions by Its Partial Inclusion into a Cyclodextrin

“…[4] On the other hand, the number of cases is certainly less where ruthenium dyes are used in dye-sensitized photoelectrochemical cells (DSPECs) for performing the demanding water oxidation reaction. [5] The two most widely used dyes are the simple [Ru(bpy)3] 2+ (bpy = 2,2'-bipyridine) and its phosphonated derivative, [Ru(4,4'-PO3H2-bpy)(bpy)2] 2+ . [6] One main reason for the lack of examples can be attributed to the low oxidation potentials of most ruthenium(II) dyes used in DSPECs, which are not high enough to charge up a suitable catalyst capable of driving the highly demanding water oxidation reaction, E 0 (O2/H2O) = 1.23 -0.059 x pH vs. NHE.…”