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 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-existance 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 responsible for vanadium clustering, which results in the irreversible deactivation of the catalyst.