Sujing Li, Shan Tan, Yun shi and Wei Li
College of chemical and biological engineering, Zhejiang University, Hangzhou, Zhejiang, China
Activated carbon derived from sargassum(SAC), normally disposed as waste, has been examined as potential catalysts for selective catalytic reduction (SCR) of NO with NH3 in the temperature range of 50-250 °C. The influence of preparation methods, phosphoric acid impregnation ratios and surface nitrogen functional groups, were investigated. An array of analytical techniques, including BET, SEM-EDX, EA, FTIR and XPS, were also employed to study the structural properties, elemental content, and distribution of nitrogen-containing groups of the catalyst prepared.
The N-modified SAC samples presented higher catalytic activity than the virgin SAC samples. The N-doped commercial activated carbon(NCAC) achieved a maximum NOx conversion of 75% at 150 °C and then decreased to 55% at 250 °C. NOx conversion was maintained above 75% and achieved a maximum of 87% at 150 °C for the NSAC. Besides, N2 selectivity was maintained above 95%. In conclusion, the activated carbons prepared from sargassum could be used as an alternative of the commercial AC. Moreover, the modification with urea on the SAC leads to the increase of its SCR activity and N2 selectivity.
Keywords: Activated carbon, SCR, catalyst, low temperature