Simple physical mixing of zeolite prevents sulfur deactivation of vanadia catalysts for NOx removal

• Published in: Nature communications Vol. 12; no. 1; p. 901
• Main Authors: Song, Inhak, Lee, Hwangho, Jeon, Se Won, Ibrahim, Ismail A. M., Kim, Joonwoo, Byun, Youngchul, Koh, Dong Jun, Han, Jeong Woo, Kim, Do Heui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.02.2021; Nature Publishing Group
• Subjects: 119/118; 147/143; 639/301/299/1013; 639/638/77/885; 639/638/77/887; Aging; Ammonia; Ammonium; Catalysis; Catalysts; Chemical reduction; Deactivation; Dew point; Humanities and Social Sciences; Industrial plants; Low temperature; multidisciplinary; Porosity; Regeneration; Science; Science (multidisciplinary); Selective catalytic reduction; Sulfur; Titanium dioxide; Trapping; Vanadium; Vanadium pentoxide; Vanadium pentoxide-Titanium dioxide; Zeolites
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-21228-x

NO x abatement has been an indispensable part of environmental catalysis for decades. Selective catalytic reduction with ammonia using V 2 O 5 /TiO 2 is an important technology for removing NO x emitted from industrial facilities. However, it has been a huge challenge for the catalyst to operate at low temperatures, because ammonium bisulfate (ABS) forms and causes deactivation by blocking the pores of the catalyst. Here, we report that physically mixed H-Y zeolite effectively protects vanadium active sites by trapping ABS in micropores. The mixed catalysts operate stably at a low temperature of 220 °C, which is below the dew point of ABS. The sulfur resistance of this system is fully maintained during repeated aging/regeneration cycles because the trapped ABS easily decomposes at 350 °C. Further investigations reveal that the pore structure and the amount of framework Al determined the trapping ability of various zeolites. V-based NO x abatement systems are limited in operating at low-temperatures due to the formation of ammonium bisulfate that blocks active sites of catalysts. Here, the authors report that physically mixed zeolites trap ammonium bisulfate in their micropores, thereby protecting the catalysts.