The interactions of two-dimensional vanadium oxide and molybdenum oxide overlayers with the surface hydroxyls of an alumina support were examined with 'H MAS NMR spectroscopy. The measurements demonstrated that these surface metal oxide overlayers are homogeneously distributed over the alumina surface and essentially titrate all the accessible surface hydroxyls at monolayer coverage. The invest...

The molecular structures of the surface overlayers of rhenium(VI1) oxide, molybdenum(V1) oxide, tungsten(V1) oxide, chromium(V1) oxide, vanadium(V) oxide, niobium(V) oxide, and titanium( IV) oxide on y-alumina were determined by in situ Raman spectroscopy under dehydrated conditions. It was found that the dehydrated surface metal oxide structures of all the systems under study, except for suppo...

Niobia/alumina model catalysts were prepared by physical vapor deposition of Nb in an oxygen atmosphere onto thin alumina films. Structural characterization, performed with scanning tunneling microscopy and infrared reflection absorption spectroscopy, revealed highly dispersed N2O5 nanoparticles exposing Nb=O groups. Thermal stability of the system was also examined. The results are compared wi...

Bimetallic Mo-Fe and Mo-Co sulfide clusters were anchored on AI,O, and used for CO hydrogenation. In addition to methane, significant amounts of dimethyl ether were produced. The reaction orders obtained from power rate laws for methanation indicated that the surfaces of the catalytic ensembles were not completely saturated by CO, in contrast to the observations for most conventional CO hydroge...

Nanofiltration with inorganic meso-porous membranes is being considered more and more for water purification applications. For specific applications inorganic membranes may have advantages over organic polymer-based membranes due to their rigid pore structure, and thermochemical stability. However, the permeability and, partly through that, the permselectivity of inorganic membranes need to be ...