Using ultrasound to improve the sequential post-synthesis modification method for making mesoporous Y zeolites  

作　　者：Rongxin Zhang Peinan Zhong Hamidreza Arandivan Yanan Guan Jinmin Liu Na Wang Yilai Jiao Xiaolei Fan 

机构地区：[1]Department of Chemical Engineering and Analytical Science,School of Engineering,The University of Manchester,Manchester,M139PL,UK [2]Laboratory of Advanced Catalysis for Sustainability,School of Chemistry,The University of Sydney,Sydney 2006,Australia [3]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [4]Sino-Spanish Advanced Materials Institute,Shenyang University of Chemical Technology,Shenyang 110142,China [5]Advanced Manufacturing Institute of Polymer Industry(AMIPI),Shenyang University of Chemical Technology,Shenyang 110142,China [6]Key Laboratory of Materials and Advanced Equipment for Resource Chemical Technology(Ministry of Education),Shenyang University of Chemical Technology,Shenyang 110142,China

出　　处：《Frontiers of Chemical Science and Engineering》2020年第2期275-287,共13页化学科学与工程前沿（英文版）

基　　金：Yilai Jiao thanks the China Scholarship Council for his academic visiting fellowship in the UK(File No.201604910181);Na Wang thanks the National Natural Science Foundation of China(Grant No.51973124)for supporting her research.

摘　　要：Mesoporous Y zeolites were prepared by the sequential chemical dealumination(using chelating agents such as ethylenediaminetetraacetic acid,H EDTA,and citric acid aqueous solutions)and alkaline desilication(using sodium hydroxide,NaOH,aqueous solutions)treatments.Specifically,the ultrasound-assisted alkaline treatment(i.e.,ultrasonic treatment)was proposed as the alternative to conventional alkaline treatments which are performed under hydrothermal conditions.In comparison with the hydrothermal alkaline treatment,the ultrasonic treatment showed the comparatively enhanced efficiency(with the reduced treatment time,i.e.,5 min vs.30 min,all with 0.2 mol·L NaOH at 65°C)in treating the dealuminated Y zeolites for creating mesoporosity.For example,after the treatment of a dealuminated zeolite Y(using 0.1 mol·L H EDTA at 100°C for 6 h),the ultrasonic treatment produced the mesoporous zeolite Y with the specific external surface area()of 160 m·g and mesopore volume()of 0.22 cm·g,being slightly higher than that by the conventional method(i.e.,=128 m·g and=0.19 cm·g).The acidic property and catalytic activity(in catalytic cracking of-octane)of mesoporous Y zeolites obtained by the two methods were comparable.The ultrasonic desilication treatment was found to be generic,also being effective to treat the dealuminated Y zeolites by citric acid.Additionally,the first step of chemical dealumination treatment was crucial to enable the effective creation of mesopores in the parent Y zeolite(with a silicon-to-aluminium ratio,Si/Al=2.6)regardless of the subsequent alkaline desilication treatment(i.e.,ultrasonic or hydrothermal).Therefore,appropriate selection of the condition of the chemical dealumination treatment based on the property of parent zeolites,such as Si/Al ratio and crystallinity,is important for making mesoporous zeolites effectively.

关 键 词：ZEOLITE Y MESOPOROUS ZEOLITE post-synthesis TREATMENT ULTRASOUND chemical DEALUMINATION TREATMENT alkaline DESILICATION TREATMENT 

分 类 号：O64[理学—物理化学]