Development and characterization of thermally stable supported V–W–TiOcatalysts for mobile NH–SCR applications

Vanadium based catalysts supported on a mixture of tungsten and titanium oxide (V2O5/WO3–TiO2) are known to be highly active for ammonia selective catalytic reduction (NH3–SCR) of NOx species for heavyduty mobile applications. However they are also known to be sensitive to high temperatures which leads to both sintering of the anatase TiO2 support and a first order phase transition to rutile at temperatures .600uC. Here we report our attempts to use SiO2 to stabilize the TiO2 anatase phase and to compare its catalytic activity with that of a non-stabilized V2O5/WO3–TiO2 catalyst after thermal aging up to 800uC. Detailed characterization using spectroscopic (Raman, UV–vis, X-ray absorption spectroscopy), scattering and techniques providing information on the catalytic surface (Brunauer–Emmet–Teller, NH3 adsorption) have also been performed in order to understand the impact of high temperatures on component speciation and the catalytic interface. Results show that non-stabilized V2O5/WO3–TiO2 catalysts are initially stable after thermal aging at 600uC but on heating above this temperature a marked drop in catalytic activity is observed as a result of sintering and phase transformation of Anatase into Rutile TiO2 and phase segregation of initially highly dispersed WO3 and polymeric V2O5 into monoclinic WO3 and V2O3 crystallites. Similar behavior was observed for the 4–5 wt-% of SiO2-stabilised sample after aging above 700uC, importantly therefore, offset by some y100uC in comparison to the unstabilised sample

Genitourinary Pathology (Including Adrenal Gland)

Our aims in constructing the Genitourinary Pathology chapter are to describe neoplasms of the adrenal gland, urothelial tract, kidney, penis, prostate, and testis in a manner that is both useful for the practicing surgical pathologist and that may be used as a reference for all students of urologic pathology. Whereas the text and figures describe the salient morphologic, immunohistochemical, and molecular attributes for each tumor type and encompass the latest classification schemes, the narrative integrates the clinical and pathological findings that are commonly encountered during surgical pathology sign-out of these cases. Accordingly, it is our hope that this chapter will serve as a guide for both general and subspecialized pathologists in contemporary practice