Synthesis of HZSM-5 coatings on the inner surface of stainless steel tubes and their catalytic performance in n-dodecane cracking

Authors:  Li Wang, Ying Wang, Jiangge Hao, Guozhu Liu, Xuesong Ma, Shenlin Hu

Abstract:
HZSM-5 zeolite coatings on the inner surface of stainless steel tubes (2 mm i.d., 350 mm length) were prepared by the secondary growth method and characterized by XRD, SEM and in situ FT-IR. The catalytic performance ofthe resulting HZSM-5 coatings was evaluated using the catalytic cracking of n-dodecane at 4 MPa and 525^◦C (supercritical conditions) as a model reaction. With the repeated time of the secondary growth from 1 to 4, the mean thickness of HZSM-5 layers increased from 5.74 to 13.75 m, together with an increase in the density. Over the zeolite coating of the third growth with suitable thickness (11.63 m) and density, a high conversion of n-dodecane was achieved. The NaOH-treatment on HZSM5 zeolite layers induced the creation of meso-pores in the HZSM-5 layer, thus enhanced its catalytic activity. These experimental findings demonstrated that a balance between the thickness and diffusivity of the HZSM-5 layer benefits its catalytic activity.

Keywords:
HZSM-5 coating
Secondary growth
Catalytic cracking
Alkali-treatment
n-Dodecane

Published in: Applied catalysis A: General  (Volumes 462–463, Pages 1-310, 10 July 2013)

Publisher: Elsevier      

ISSN Information: 0926-860X

Synthesis of HZSM-5 coatings on the inner surface of stainless steel tubes and their catalytic performance in n-dodecane cracking

Bình luận của bạn

*

*

*

*

 Captcha

Gửi bình luận nhập lại