Reactions of Neutral Vanadium Oxide Clusters with Methanol

Reactions of neutral vanadium oxide clusters with methanol and ethanol in a fast-flow reactor are investigated by time-of-flight mass spectrometry. Single-photon ionization through soft X-ray (46.9 nm, 26.5 eV) and vacuum ultraviolet (VUV, 118 nm, 10.5 eV) lasers is employed to detect both neutral Cluster distributions and reaction products. In order to distinguish isomeric products generated in the reactions VmOn + CH3OH, partially deuterated methanol (CD3OH) is also used as a reactant in the experiments. Association products are observed for most vanadium oxide clusters in reaction with methanol. Products VOD, V2O3D, V3O6D, and V4O9D are observed for oxygen-deficient vanadium oxide clusters reacting with methanol, while oxygen-rich and the most stable clusters can extract more than one hydrogen atom (H/D) from CD3OH to form products VO2DH0.1, V2O4DH0.1, V2O5DH0.1, V3O7DH0.1, and V4O10DH0.1. Species VO2(CH3)(2), VO3(CH3)(2), V2O5(CH3)(2), V3O7(CH3)(2), and V3O8(CH3)(2) are identified as some of the main products generated from a dehydration reaction for VmOn + CH3OH. A minor reaction channel that generates VOCH2O (VOCD2O) and VO2CH2O (VO2CD2O) can also be identified. An obviously different behavior appears in the reaction VmOn + C2H5OH. The main observed products for this reaction are association products of the form VmOnC2H5OH. In order to explore the mechanism of VmOn + CH3OH reactions, DFT calculations are performed to study the reaction pathways Of VO2 + CH3OH and VO + CH3OH reaction systems. The calculation results are in good agreement with the experimental observations.