Synthesis of acidic-basic Y zeolite from kaolin: catalytic and mechanism study in the cracking of polyethylene

doi:10.1039/d4ra08978b

IMR OpenIR

	Synthesis of acidic-basic Y zeolite from kaolin: catalytic and mechanism study in the cracking of polyethylene
	Motamadnejad, Samira 1; Gao, Li 2; Heydar, Kourosh Tabar 1; Panahi, Reza 1; Zhang, Bingsen 2; Shakeri, Mozaffar 1
通讯作者	Shakeri, Mozaffar(m.shakeri@ccerci.ac.ir)
	2025-02-13
发表期刊	RSC ADVANCES
卷号	15 期号:7 页码:4861-4873
摘要	Cracking of plastic waste by the acidic FAU-type zeolites faces challenges of low production of light olefins, a high amount of coke formation, and expensive process. Basic zeolites might be a better alternative; however, their preparation is difficult and the related cracking mechanism is unknown. We addressed these difficulties by direct synthesis of a hierarchical acidic-basic FAU-type zeolite (HY-BS) using silica extracted from a low-grade kaolin containing alkaline (earth) metals and investigated the impact of basicity in the linear low density polyethylene (LLDPE) cracking mechanism and products distribution. Compared to an acidic HY zeolite, the HY-BS presented comparable density of Br & oslash;nsted acidity but a drastically higher density of the basicity. The HY-BS had comparable activity to the reference HY zeolite, but it produced twice light olefins (30.5 vs. 16.2%), triple lighter aromatics (41.0 vs. 13.8%), and less coke in LLDPE cracking. The thermodynamic investigation of thermal and zeolitic cracking of LLDPE was conducted based on the TGA results, along with kinetic analysis using four model-free techniques and a differential method. According to kinetic and thermodynamic parameters and product distribution, the HY-BS exhibited a dual cracking pathway that first followed a carbocation mechanism before switching to a radical mechanism as the reaction progressed, accounting for the reason behind improved light olefins selectivity. Consequently, direct promotion of the basicity of the zeolites synthesized from impure kaolin was effective to overcome difficulties facing plastic waste cracking.
资助者	National Natural Science Foundation of China ; Iran National Science Foundation ; National Natural Science Foundation of China
DOI	10.1039/d4ra08978b
收录类别	SCI
语种	英语
资助项目	National Natural Science Foundation of China[4001399] ; Iran National Science Foundation[52161145403] ; National Natural Science Foundation of China
WOS研究方向	Chemistry
WOS类目	Chemistry, Multidisciplinary
WOS记录号	WOS:001419213000001
出版者	ROYAL SOC CHEMISTRY
引用统计
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/180013
专题	中国科学院金属研究所
通讯作者	Shakeri, Mozaffar
作者单位	1.Chem & Chem Engn Res Ctr Iran, Lab Heterogeneous Catalysis, POB 1497716363, Tehran, Iran 2.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Motamadnejad, Samira,Gao, Li,Heydar, Kourosh Tabar,et al. Synthesis of acidic-basic Y zeolite from kaolin: catalytic and mechanism study in the cracking of polyethylene[J]. RSC ADVANCES,2025,15(7):4861-4873.
APA	Motamadnejad, Samira,Gao, Li,Heydar, Kourosh Tabar,Panahi, Reza,Zhang, Bingsen,&Shakeri, Mozaffar.(2025).Synthesis of acidic-basic Y zeolite from kaolin: catalytic and mechanism study in the cracking of polyethylene.RSC ADVANCES,15(7),4861-4873.
MLA	Motamadnejad, Samira,et al."Synthesis of acidic-basic Y zeolite from kaolin: catalytic and mechanism study in the cracking of polyethylene".RSC ADVANCES 15.7(2025):4861-4873.