TY - JOUR
T1 - Non-oxidative dehydrogenation of isobutane over supported vanadium oxide: Nature of the active sites and coke formation
AU - Rodriguez-Gomez, Alberto
AU - Chowdhury, Abhishek Dutta
AU - Caglayan, Mustafa
AU - Bau, Jeremy
AU - Abou-Hamad, Edy
AU - Gascon, Jorge
N1 - KAUST Repository Item: Exported on 2020-11-10
Acknowledgements: This work is funded by King Abdullah University of Science and Technology (KAUST). We also thank Sandra Ramirez Cherbuy for TOC art.
PY - 2020/7/1
Y1 - 2020/7/1
N2 - We combine Raman spectroscopy, electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), X-ray diffraction (XRD), high-field 51V-solid-state magic angle spinning NMR spectroscopy (ssNMR), transmission electron microscopy (TEM) and N2-physisorption to unravel structure-activity relationships during the non-oxidative dehydrogenation of isobutane over a V-based catalyst. The use of SBA-15 as a support favours the formation of oligomeric tetrahedral VOx species along with a smaller amount of V2O5 clusters. EPR, 51V-ssNMR and XPS suggest the formation of mostly V4+ species under reaction conditions. Investigation of "coke"species by dynamic nuclear polarization surface enhanced solid-state NMR (DNP SENS) reveals the co-existence of aliphatic, olefinic/aromatic, acetal/alkoxy and carbonyl-based organic moieties in the post-reacted catalyst. Together with TPR and XRD results, we postulate that oxygenated coke species are the main components responsible for vanadium clustering, which results in the irreversible deactivation of the catalyst.
AB - We combine Raman spectroscopy, electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), X-ray diffraction (XRD), high-field 51V-solid-state magic angle spinning NMR spectroscopy (ssNMR), transmission electron microscopy (TEM) and N2-physisorption to unravel structure-activity relationships during the non-oxidative dehydrogenation of isobutane over a V-based catalyst. The use of SBA-15 as a support favours the formation of oligomeric tetrahedral VOx species along with a smaller amount of V2O5 clusters. EPR, 51V-ssNMR and XPS suggest the formation of mostly V4+ species under reaction conditions. Investigation of "coke"species by dynamic nuclear polarization surface enhanced solid-state NMR (DNP SENS) reveals the co-existence of aliphatic, olefinic/aromatic, acetal/alkoxy and carbonyl-based organic moieties in the post-reacted catalyst. Together with TPR and XRD results, we postulate that oxygenated coke species are the main components responsible for vanadium clustering, which results in the irreversible deactivation of the catalyst.
UR - http://hdl.handle.net/10754/665864
UR - http://xlink.rsc.org/?DOI=D0CY01174F
UR - http://www.scopus.com/inward/record.url?scp=85094972979&partnerID=8YFLogxK
U2 - 10.1039/d0cy01174f
DO - 10.1039/d0cy01174f
M3 - Article
SN - 2044-4761
VL - 10
SP - 6139
EP - 6151
JO - Catalysis Science and Technology
JF - Catalysis Science and Technology
IS - 18
ER -