Characterization of CeO2-WO3 catalysts prepared by different methods for selective catalytic reduction of NOx with NH3

In this work, cerium-tungsten oxide catalysts were prepared by three methods: single step sol-gel (SG), impregnation (IM), and solid processing (SP). The catalysts were used for selective catalytic reduction (SCR) of NOx with ammonia over a wide temperature range. The results indicated that the catalysts prepared by the SP and IM methods exhibited better SCR activity than that prepared via the SG method in 175-500 °C. The excellent activity can be attributed to larger surface area, higher surface concentrations of Ce and Ce3 +, enhanced NO oxidization ability, and greater number of surface acid sites.