NH3-SCR performance of WO3 blanketed CeO2 with different morphology: Balance of surface reducibility and acidity

An environmental benign WO3 Blanketed CeO2 catalyst, the W@Ce, was prepared via a two-step hydrothermal impregnation method for the NOx removal. The WO3 was deposited on CeO2 nanocube (C), nanoparticle (P), and nanorod (R). The W@Ce-P exhibited the highest SCR activity below 300 degrees C with considerable resistance to H2O and SO2. Compared with the W@Ce-C and W@Ce-R, the NO conversion (at 200 degrees C) of the W@Ce-P increased by 11% and 38%, respectively. The W@Ce-P were mainly dominated with the (111) facets which have the highest SCR activity. Meanwhile, the W@Ce-P performed good adsorption properties of ammonia at 125-450 degrees C, and exhibited more surface lattice oxygen O2- than that of the W@Ce-C and W@Ce-R. Thus, the surface reducibility and acidity were enhanced at lower temperature, which benefits the SCR reaction. The CeO2 nanoparcles and WO3 particles showed good interaction and had well-distributed and similar particle size. However, CeO2 nanocubes did not interact well with WO3, besides, more cerium and tungsten species are at lower valence state on the surface of the W@Ce-R.