0000000000466384
AUTHOR
Rongrong Zhao
Fe-doped Beta zeolite from organotemplate-free synthesis for NH3-SCR of NOx
Two types of Beta zeolites, one from organotemplate-free synthesis with a Si/Al ratio of 9 and the other from a commercial one with a Si/Al ratio of 19, were employed here to dope Fe for NH3-SCR of NOx. Fe-Beta (Si/Al = 9) exhibits much higher activity than Fe-Beta (Si/Al = 19), especially at low-temperature regions (<250 °C). In addition, it also exhibits better hydrothermal stability as compared with Fe-Beta (Si/Al = 19), which demonstrates that it is a promising SCR catalyst with good activity as well as hydrothermal stability. The correlation between the quantitative calculation of the content of isolated Fe3+ in Beta zeolites and the NO conversion rate at 150 °C shows a linear relation…
Cu-exchanged Al-rich SSZ-13 zeolite from organotemplate-free synthesis as NH3-SCR catalyst: Effects of Na+ ions on the activity and hydrothermal stability
Abstract The relatively low activity at lower temperatures and high cost of SSZ-13 zeolite from organotemplate synthesis are two of major problems of presently commercialized Cu-SSZ-13 catalysts for NH3-SCR reaction. Cu-exchanged Al-rich SSZ-13 catalysts with Si/Al = 4 from organotemplate-free synthesis have been prepared, and show superior NH3-SCR performance with NO conversions above 85% at wide-temperature window ranging from 150 to 650 °C. Cu-Na-SSZ-13 catalysts with varied amount of residual Na+ were prepared by partial ion-exchange of as-prepared Al-rich Na-SSZ-13, and it’s found that Cu-Na-SSZ-13 catalyst with moderate Na+ content can improve both the low-temperature activity and its…