Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases p. 2777 - 2802 (1981)
Update date:2022-08-16
Topics:
Cunningham, Joseph
Hodnett, Benjamin K.
Kinetics of conversion of propan-2-ol and butan-2-ol to the corresponding ketones by photoassisted dehydrogenation, (-H2)*, to lower aldehydes by a photoassisted Cα-Cβ bond cleavage process, (α-β)*, and to trace quantities of alkene by photoassisted dehydration (-H2O)* have been investigated at oxygen partial pressures in the range 0-700 Torr and at alcohol partial pressures of 0-60 Torr, utilising dynamic flow photoreactors and gas-chromatographic analysis.Qualitatively similar results were obtained either with a 'continuous reactant flow plus continuous u.v. illumination' procedure allied to intermittent sampling, or with a 'pulsed reactant and analysis' procedure.Both procedures yielded dependence upon alcohol pressure indicative of two parallel photoassisted pathways to (-H2)* product, one being Langmuir-Hinshelwood (LH*) and the other Eley-Rideal (ER*) in character.A decline in activity of the metal oxide surfaces as photoassisted conversion of alcohol increased was observed with both procedures and affected the LH* process for (-H2)* more strongly.It is proposed that this LH* process involved alcohol chemisorption and hole localisation at coordinatively unsaturated O2-cus ions.The ER* process is envisaged to have involved encounter of alcohol (from the gas phase or from a reversibly adsorbed weakly bound state) with a much more numerous type of surface location capable of being photoactivated by hole capture.The proposed mechanisms account for observed dependences of the (-H2)* process upon square root of the incident light intensity, upon alcohol pressure and upon oxygen pressure.
View MoreContact:+86-13914766747
Address:Floors 21&22, Jin Cheng Tower, No. 216 Middle Longpan Road, Nanjing
Wuhan Yitongtai Science and Technology Co.,Ltd.
Contact:+86-27-88933550
Address:27th Fl. Bldg. 1, Shuian International Mansion, Heping Ave, Wuhan, Hubei, China
Tianjin Te-An Chemtech Co., Ltd.(expird)
Contact:+86-22-65378638
Address:A5-8, No.80 Haiyun Street, TEDA
Contact:+86-025-52406782
Address:8 Taizishan Rd., Yanjiang Industrial Development Area, Nanjing, Jiangsu, China.
Chengdu ZY Biochemical Technology Co., LTD
Contact:0086-28-88680086
Address:170 Qingpu Road, Shouan Town, Pujiang County
Doi:10.1016/j.apcata.2011.11.016
(2012)Doi:10.1016/j.ejmech.2016.08.062
(2016)Doi:10.1002/anie.202005765
(2020)Doi:10.1039/c39780000068
(1978)Doi:10.1246/cl.1982.385
(1982)Doi:10.1016/j.tetlet.2019.151215
(2019)
