摘要
采用水热合成法制备了普通和具有分级孔结构的ZSM-5分子筛,采用XRD、N_2吸附-脱附、SEM、NH_3-TPD及Py-IR等手段对分子筛的晶体结构、孔结构、微观形貌和酸性进行了表征,并在连续流动固定床反应器上对其催化甲醇转化制烃的活性、稳定性及再生性能进行了评价。表征和评价结果表明,除了酸性,孔结构对催化剂的稳定性也有重要影响。粒径分布均匀的纳米ZSM-5分子筛的晶粒相互堆积形成了次级中孔和大孔,与其自身的微孔构成分级孔结构,具有较大的孔体积(0.49 cm^3/g)。分级孔结构改善了催化剂的扩散性能,极大增强了催化剂的抗积碳能力,使催化剂的寿命由24h延长至336h。
A normal ZSM-5 zeolite and three ZSM-5 zeolites with hierarchical pores were synthesized by hydro-thermal method,and characterized by means of XRD,N2 adsorption-desorption,SEM,NH3-TPD and Py-IR to get the information about their crystal structure,pore structure,morphology and acidity. The performances of the ZSM-5 zeolite catalysts in methanol to hydrocarbons were investigated in a continuous flow fixed bed reactor. It was showed that the acidity and pore structure of the ZSM-5 zeolites had important effects on their stability in the catalytic reactions. The well-distributed nano crystal grains of the ZSM-5 zeolites formed secondary mesopores and macropores,and these pores and their inherent micropore constructed hierarchical pore structure with larger pore volume（up to 0.49 cm^3/g）,which could improve the diffusion property of the zeolite catalysts and greatly enhanced their resistance to carbon deposition. So the catalyst life was prolonged from 24 h to 336 h.
出处
《石油化工》
CAS
CSCD
北大核心
2017年第3期276-282,共7页
Petrochemical Technology
基金
中国科学院战略性先导专项资助项目(XDA-07070400)
关键词
ZSM-5分子筛催化剂
分级孔道
甲醇
烃
积碳
ZSM-5 zeolite catalyst
hierarchical pore
methanol
hydrocarbon
carbon deposition
