VO Cluster-Stabilized HO Adsorption on a TiO (110) Surface at Room Temperature.

We probe the adsorption of molecular HO on a TiO (110)-(1 × 1) surface decorated with isolated VO clusters using ultrahigh-vacuum scanning tunneling microscopy (UHV-STM) and temperature-programmed desorption (TPD). Our STM images show that preadsorbed VO clusters on the TiO (110)-(1 × 1) surface induce the adsorption of HO molecules at room temperature (RT). The adsorbed HO molecules form strings of beads of HO dimers bound to the 5-fold coordinated Ti atom (5c-Ti) rows and are anchored by VO.

Catalytic oxidation of methanol to formaldehyde by mass-selected vanadium oxide clusters supported on a TiO2(110) surface.

We report the results of a systematic study of the catalytic activity of mass-selected vanadium oxide clusters deposited on rutile TiO2 surfaces under ultrahigh vacuum (UHV) conditions. Our results show that supported V, VO, and VO2 clusters are not catalytically active for the oxidative dehydrogenation of methanol to formaldehyde but can be made catalytically active by postoxidation. In addition, we found that the postoxidized VO/TiO2 produces the most formaldehyde.