High performance of the morphologically controlled synthesis carrier of TiO2 for NH3 selective catalytic reduction of NO

TiO2 supported Ni and Ce with different morphologies (particle-like TiO2 (PT), flower-like TiO2 (FT), spherical like TiO2 (ST), rod-like TiO2 (RT)) were prepared. Ni-Ce/flower-like TiO2 (NCFT) catalyst exhibits the performance (NO conversion and N-2 selectivity both approach to 100% approximately) in 250-450 degrees C and resistance (similar to 80%). The sequence of activities is NCFT > NCST > NCPT > NCRT. The FT carrier provides largest specific surface area (145.9 m(2) g(-1)), facilitating the dispersion of the active components. In addition, NCFT is abundant in Ni3+ and Ce3+ as well as O alpha species, which support excellent redox properties. More weak acid and medium acid sites provided more adsorption sites for NH3-SCR reaction. This is also the main reason that NCFT catalyst has excellent denitrification activity. In-situ infrared results show that the reaction of NCFT catalyst is mainly through E-R mechanism, and NH3 (L) and -NH2 species formed on the catalyst surface were main ammonia adsorption species and reaction species. Unfortunately, NCFT has not ideal sulfur resistance stability due to its unique structure, which needs to be further improved.

Automated summary

In this study, TiO2 supported Ni and Ce catalysts with different morphologies were prepared. The Ni-Ce/flower-like TiO2 (NCFT) catalyst showed high performance (approximately 100% NO conversion and N-2 selectivity) in the temperature range of 250-450 degrees C, with resistance of around 80%. The order of activities observed was NCFT > NCST > NCPT > NCRT. The flower-like TiO2 carrier provided the largest specific surface area, facilitating the dispersion of active components. NCFT also exhibited excellent denitrification activity due to its abundance in Ni3+, Ce3+, and O alpha species, which supported excellent redox properties and provided more adsorption sites for the NH3-SCR reaction. However, its sulfur resistance stability needs further improvement due to its unique structure.