Effect of framework single and close (pairs and un-pairs) aluminum atoms on phosphorous modification of HZSM-5 in cracking of liquefied petroleum gas to ethylene and propylene

- HZSM-5 zeolites with different Al distributions in the framework were synthesized.
- The zeolites with various single Al atoms were modified with phosphorus and steam.
- Higher single Al atoms in the framework enhanced olefin yields and P/E ratio.
- The reduction of strong acid sites increased catalytic stability and olefin yields.
- The highest olefin yield was 47.33% for P/St/HZSM-5(1) with lowest strong acidity.