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.

Graphical abstractThe effect of zeolite treatment on the total conversion of NOx into N2 as a function of reaction temperature and zeolite treatment procedure.Figure optionsDownload full-size imageDownload as PowerPoint slide