We report for the first time the effect of clinoptilolite dealumination on the propane–SCR–NOx process.
This has been accomplished using a mild acid like oxalic acid to avoid excess catalyst crystallinity deterioration. It had been shown that dealumination may result in a significant enhancement of NOx conversion to N2 when an optimum acid concentration of 0.050 M is used for a treatment period of 2 h.
Dealumination substantially affects the distribution of the concentration of acid sites of different
strength. The effect of dealumination on the HC-SCR activity of the zeolite samples is discussed in terms
of Si/Al ratio, crystallinity, distribution of acid site strength, extra framework species concentration and
textural characteristics of the samples.