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We have completed an exploratory study of the synthesis of terephthalic acid via the partial oxidation of p-xylene in liquid water at temperatures ranging from 250 to 350°C. The reactions occurred in 1.54 mL stainless steel batch reactors, and the batch holding time was 60 min. We determined the influence of temperature, catalyst identity, p-xylene initial concentration, and oxidant initial concentration on the yield of terephthalic acid and intermediate products. The catalysts included in this study were manganese bromide, cobalt bromide, manganese acetate, nickel bromide, hafnium bromide, and zirconium bromide. Hydrogen peroxide was the oxidant. The maximum yield of terephthalic acid, 49 ( 8%, occurred at 300°C with manganese bromide as the catalyst. Other catalysts or catalyst combinations produced lower yields. Yields of terephthalic acid decreased as the oxidant-to-p-xylene ratio decreased, either by increasing the initial concentration of p-xylene or by decreasing the initial concentration of oxidant.

The growing need for alternative sources of transportation fuels encourages the development of new hydrotreatment catalysts. These catalysts must be active and more hydrogen efficient than the current commercial hydrotreatment catalysts. Molybdenum nitrides and carbides are attractive candidate materials possessing properties that are comparable or superior to those of commercial sulfide catalysts. This research investigated the catalytic properties of γ-Al 2 O 3supported molybdenum nitrides and carbides. These catalysts were synthesized via temperatureprogrammed reaction of supported molybdenum oxides with ammonia or methane/hydrogen mixtures. Phase constituents and compositions were determined by X-ray diffraction, elemental analysis, and neutron activation analysis. Oxygen chemisorption was used to probe the surface properties of the catalysts. Specific activities of the molybdenum nitrides and carbides were competitive with those of a commercial sulfide catalyst for hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and hydrodeoxygenation (HDO). For HDN and HDS, the catalytic activity on a molybdenum basis was a strong inverse function of the molybdenum loading. Product distributions for the HDN, HDO, and HDS of a variety of heteroatom compounds indicated that several of the nitrides and carbides were more hydrogen efficient than the sulfide catalyst.