Imperial College London
Prof. David Chadwick

Prof. David Chadwick

Faculty of Engineering, Department of Chemical Engineering

Professor
 
 
 
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Contact

 

+44 (0)20 7594 5579d.chadwick

 
 
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Location

 

235Roderic Hill BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Graça:2018:10.1016/j.apcata.2018.09.025,
author = {Graça, I and Al-Shihri, S and Chadwick, D},
doi = {10.1016/j.apcata.2018.09.025},
journal = {Applied Catalysis A: General},
pages = {95--104},
title = {Selective oxidation of cyclohexane: Ce promotion of nanostructured manganese tungstate},
url = {http://dx.doi.org/10.1016/j.apcata.2018.09.025},
volume = {568},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Cyclohexane selective oxidation over nanostructured MnWO4promoted with increasing amounts of Ce (1–5 wt%) has been investigated at mild conditions using molecular oxygen as oxidant. MnWO4nanorods were found to be an active catalyst for cyclohexane selective oxidation with selectivity to KA oil (cyclohexanol + cyclohexanone) of approximately 85%. The catalytic performance was improved by impregnation with 1 wt% Ce while the textural properties and crystallinity were preserved and Ce was well-dispersed on the surface. XPS analysis of 1%Ce-MnWO4showed Ce to be present mainly as Ce3+, which is known to promote oxygen adsorption, activation, and mobility. At higher Ce content, the proportion of Ce4+increased to be the main Ce species and large, heterogeneously-dispersed Ce oxide particles are formed on the catalyst surface. The lower Ce3+content reduces the promoting effect while the large Ce oxide particles block access to the active sites on the surface of the MnWO4nanorod. MnWO4and 1%Ce-MnWO4nanorods were shown to retain their selective oxidation performance in consecutive reaction runs. Surprisingly, physical mixtures of nanostructured MnWO4and a CeO2nanopowder showed enhanced selective oxidation activity compared to MnWO4alone reaching a plateau at 25–50 wt% CeO2, whereas CeO2nanopowder itself was found to be inactive at the reaction conditions. Ce promoted MnWO4shows promise as a catalyst for selective oxidation of cyclohexane and performs at least as well as the most active non-metallic heterogeneous catalysts reported in the literature.
AU  - Graça,I
AU  - Al-Shihri,S
AU  - Chadwick,D
DO  - 10.1016/j.apcata.2018.09.025
EP  - 104
PY  - 2018///
SN  - 0926-860X
SP  - 95
TI  - Selective oxidation of cyclohexane: Ce promotion of nanostructured manganese tungstate
T2  - Applied Catalysis A: General
UR  - http://dx.doi.org/10.1016/j.apcata.2018.09.025
UR  - https://www.sciencedirect.com/science/article/pii/S0926860X18304861
UR  - http://hdl.handle.net/10044/1/63758
VL  - 568
ER  -
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