Low-Temperature Ethylbenzene Conversion on Rutile TiO2(100) via Photocatalysis: The Strong Photon Energy Dependence

Direct dehydrogenation of alkanesunder mild conditionsoffersa green route to produce valuable olefins, but realizing C-Hbond activation at a low temperature presents a significant challenge.Here, photocatalytic ethylbenzene conversion into styrene has beenachieved by one hole on rutile (R)-TiO2(100) at80 K under 257 and 343 nm irradiation. Although the rates of the initial & alpha;-C-H bond activation are nearly the same at the twowavelengths, the rate of the & beta;-C-H bond cleavage is stronglydependent upon hole energy, leading to the much higher yield of 290K styrene formation at 257 nm, which raises doubt about the simplifiedTiO(2) photocatalysis model in which excess energy of thecharge carrier is useless and highlights the importance of intermolecularenergy redistribution in photocatalytic reactions. The result notonly advances our understandings in low-temperature C-H bondactivation but also calls for the development of a more sophisticatedphotocatalysis model.

Automated summary

Photocatalytic ethylbenzene conversion into styrene has been achieved by one hole on rutile (R)-TiO2(100) at 80 K under 257 and 343 nm irradiation. The rate of β-C-H bond cleavage is strongly dependent on hole energy, leading to a much higher yield of styrene formation at 257 nm. This result advances our understanding of low-temperature C-H bond activation and suggests the need for a more sophisticated photocatalysis model.