Structure of isolated vanadium sites in supported VOx/SiO2 catalysts according to solid-state 51V NMR spectroscopy in combination with DFT calculations

A combined approach of solid-state NMR spectroscopy and quantum chemical calculations was used to determine the detailed structure of surface vanadia sites. The VOx model representing the active site of the supported VOx/SiO2 catalyst was modeled employing solid-state ⁵¹V NMR spectroscopy and calculations performed using the GIAO (Gauge-Including Atomic Orbital) method. The GIAO method demonstrated better agreement between theoretical and experimental ⁵¹V NMR parameters compared to the GIPAW (Gauge-Including Projector Augmented Waves) method, particularly for compounds featuring short V=O bonds.