Many of the difficulties encountered in the original Fiske and SubbaRow method for estimating serum phospholid were corrected through the use of vanadium pentoxide, a catalyst used in sample digestion, and through other minor modifications. Results obtained by the modified method agree well with those obtained by three other established phospholipid procedures. The greatly improved speed, simpl...

The new hexanuclear mixed-valence vanadium complex [V(3)O(3)(OEt)(ashz)(2)(μ-OEt)](2) (1) with an N,O-donor ligand is reported. It acts as a highly efficient catalyst toward alkane oxidations by aqueous H(2)O(2). Remarkably, high turnover numbers up to 25000 with product yields of up to 27% (based on alkane) stand for one of the most active systems for such reactions.

The reaction mechanism of methanol oxidation catalyzed by vanadium oxides on a silica support (V2O5/ SiO2) was investigated in a high-throughput operando reactor coupled with a Fourier transform-infrared (FT-IR) imaging system for rapid product analysis and six parallel, in situ Raman spectroscopy probes for catalyst characterization. Up to six V2O5/SiO2 catalysts with different vanadium loadin...

Arya Stark Instructor: Dr. Scott Oliver TA: Yashar Abdollahian Chem 151L, Section 01C Abstract. In this experiment, oxobis(2,4-pentanediono)vanadium(IV) is synthesized from a mixture of vanadium(V) oxide, sulfuric acid, acetylacetone, and ethanol. The reaction took place over heat, and came to completion when the original mixture turned blue. The solution was then filtered, neutralized, and rec...

The chromium/vanadium bimetallic Phillips catalysts developed by our research group have been proved to be a promising process to produce bimodal polyethylene using a single-reactor process. The vanadium loading of CrV-1/1, CrV-1/2, and CrV-1/3 has a significant effect on the polymerization activity, product molecular weight (MW), as well as th...

Nanostructured vanadia model catalysts, i.e. highly dispersed vanadium oxide supported on mesoporous silica SBA-15 (VOx/SBA-15), were prepared. The mechanism for the synthesis of VOx/SBA-15 was elucidated by detailed characterization of the individual synthesis steps using XPS and vibrational spectrocopy. The resulting surface vanadium oxide species (0 – 2.3 V/nm), grafted on the inner pores of...

The partial oxidation of methanol to formaldehyde was studied over highly dispersed vanadia supported on mesoporous silica SBA-15 (VOx/SBA-15). VOx/SBA-15 catalysts were prepared by a novel grafting/ion-exchange method and characterized using UV-VISand Raman spectroscopy. The resulting surface vanadium oxide species (0 – 2.3 V/nm), grafted on the inner pores of the SBA-15 silica matrix, consist...

A new preparative route for vanadium phosphate catalysts is described using supercritical CO2 as an antisolvent. The amorphous microspheroidal VPO produced is shown to be more active than comparable crystalline VPO catalysts for the selective oxidation of n-butane to maleic anhydride and, furthermore, does not require an extensive pre-treatment or activation period to establish full catalytic a...

We present the V L3 near edge X-ray absorption fine structure (NEXAFS) of a vanadium phosphorus oxide (VPO) catalyst. The spe ctrum is related to the V3d-O2p hybridised unoccupied states. The overall peak position at the V L3-absorption edge is determined by the formal oxidation state of the absorbing vanadium atom. Details of the absorption fine structure are influenced by the geometric struct...