Characterization of silica-supported vanadium species. Interactions with methanol and ammonia adsorbates studied by electron spin–echo modulation spectrometry

Abstract

The interactions of deuterons in CH₃OD and CD₃OH adsorbates on V₂O₅/SiO₂ catalysts have been analysed by electron spin–echo modulation (e.s.e.m.) spectrometry. The best fit to the experimental data indicates that the tetravalent vanadium interacts with three methanol molecules with V—DO_Me= 0.27 and V—D₃C_Me= 0.35 nm in the first coordination sphere and with two farther methanol molecules at V—D₃C_Me= 0.45 nm. Fast Fourier transform of the time domain e.s.e.m. data for samples with adsorbed ND₃ clearly shows a strong interaction between vanadium and nitrogen.