Enhancement of the catalytic performance of H-clinoptilolite in propane–SCR–NOx process through controlled dealumination

• The effect of clinoptilolite dealumination on the propane–SCR–NOx process is reported.
• Dealumination was performed using oxalic acid.
• NOx conversion to N2 is enhanced significantly.
• Dealumination effect on the zeolite chemical/physical structure is assessed.

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.

The effect of zeolite treatment on the total conversion of NOx into N2 as a function of reaction temperature and zeolite treatment procedure.Figure optionsDownload as PowerPoint slide