SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF TUNGSTEN OXYNITRIDE

High surface area tungsten oxynitride has been prepared by the tempera ture programmed reaction (TPR) of WO3 with NH3. All samples were chara cterized by x-ray diffraction (XRD), nitrogen physisorption, CO chemis orption, and elemental analysis. Samples were prepared at different he ating rates (beta), and a Redhead analysis yielded an activation energ y for nitridation of 109 kJ mol(-1). A heating rate of 0.016 K s(-1) g ave optimal synthesis conditions. Solid state intermediates were studi ed by interrupting the temperature program at various stages. No disti nct suboxide phases were found using XRD. The nitridation step was det ermined to be a continuous transformation from oxide to oxynitride. Su rface area, CO uptake, and nitrogen weight % were all found to increas e as the reaction progressed. Reactivity experiments showed reasonable hydrodeoxygenation (HDO) and hydrodenitrogenation (HDN) activity, but little hydrogenation (HYD) or hydrodesulfurization (HDS) activity.