Nobel metal free, oxidant free, solvent free catalytic transformation of alcohol to aldehyde over ZnO-CeO2 mixed oxide catalyst
IR@CIMFR: CSIR-Central Institute of Mining and Fuel Research, Dhanbad
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| Title |
Nobel metal free, oxidant free, solvent free catalytic transformation of alcohol to aldehyde over ZnO-CeO2 mixed oxide catalyst
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| Creator |
Pandey, J.K.
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| Subject |
Non Coal Ventilation, Fire Gallery and Metallurgy
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| Description |
The catalytic transformation of alcohols to aldehydes under oxidant-free condition has drawn significant attention from the perspective of green chemistry. In this work, we designed noble metal free ZnO-CeO2 mixed oxide catalyst in four different ratios and tested for vapor phase benzyl alcohol dehydrogenation reaction as a model reaction under oxidant free condition. The ZnO-CeO2 mixed oxide catalyst having ratio Zn/Ce = 30/70 composition showed highest selectivity towards formation of benzaldehyde. Interestingly in addition to benzaldehyde, toluene was formed in the reaction due to hydrogenolysis of benzyl alcohol. The lowest Ce3+/Ce4+ ratio was observed from the XPS analysis of Ce(3d) core electron for the catalyst having Zn/Ce = 30/70 composition compared to others. CO2-TPD results proved that mostly the medium strength basic sites were responsible for hydrogen abstraction from benzyl alcohol producing benzaldehyde. H2-TPR results showed that ZnO-CeO2 catalyst (Zn/Ce = 30:70) had lowest reduction temperature which is in the 673 K to 573 K temperature range. The amount of toluene was higher for the ZnO-CeO2 catalyst having Zn/Ce = 40:60 ratio which had less basic sites and higher fraction of Ce3+ ion. The ZnO-CeO2 catalyst (Zn/Ce = 30:70) did not deactivate for a reaction time up to 2 h. While successive regenerations of the catalyst, toluene selectivity were increased. This may be due to the reduction of Ce4+ to Ce3+ by adsorbed hydrogen species. Also the ZnO-CeO2catalyst (Zn/Ce = 30/70) showed activity for the formation of ethanal, propanal, butanal and octanal along with corresponding alkanes from ethanol, 1-propanol, 1-butanol and 1-octanol in oxidant free condition demonstrating the in-situ generation of hydrogen. The micro kinetic analysis showed that there is no external and internal mass transfer limitation in the present case.
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| Publisher |
Elsevier
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| Date |
2016-08
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cimfr.csircentral.net/1648/1/31.%20Nobel%20metal%20free%2C%20oxydation%20free%2C%20solvent%20free%20catalytic%20transformation%20of%20alcohol.pdf
Pandey, J.K. (2016) Nobel metal free, oxidant free, solvent free catalytic transformation of alcohol to aldehyde over ZnO-CeO2 mixed oxide catalyst. Applied Catalysis A: General , 523. pp. 21-30. ISSN 0926-860X |
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| Relation |
http://dx.doi.org/10.1016/j.apcata.2016.05.003
http://cimfr.csircentral.net/1648/ |
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