Cyclohexane oxidation over Cu2O-CuO and CuO thin films deposited by CVD process on fiberglass

CH2O-CuO and CuO thin films on a fiberglass substrate were prepared by chemical vapor deposition (CVD) and then catalytically evaluated by cyclohexane oxidation. The fiber with a Cu2O-CUO film showed a high catalytic activity at low temperatures, for example 43% at 350 degreesC, and a good selectivity to cyclohexanol production (37% at 300 degreesC). The fiber with a CuO film.exhibited a higher catalytic activity, for example 48% at 350degreesC, with a high yield of cyclohexanone (37% at 250degreesC). A CuO/SiO2 catalyst with the same CuO content gave a result similar to the CuO/fiberglass system under the same conditions examined but, on the other hand cyclohexane was cleaved giving a higher selectivity to hexenes, 30% at 250degreesC. The effect of reaction temperature on the catalytic activity and selectivity of cyclohexane oxidation were investigated. At 300 degreesC the steady-state catalytic performance of the CuO/fiberglass experienced a slight deactivation after 4 It time-on stream from 40% to 38% of conversion, after which, the catalyst could be reused apparently without any activity loss. (C) 2002 Elsevier Science B.V. All rights reserved.