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分级孔ZSM-5分子筛催化甲醇转化制烃类的稳定性
Stability of ZSM-5 zeolite catalysts with hierarchical pores for methanol to hydrocarbons
【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、N2吸附-脱附、SEM、NH3-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 cm3/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。
【Abstract】 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 adsorptiondesorption,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 cm3/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 24h to 336h.
【Key words】 ZSM-5 zeolite catalyst; hierarchical pore; methanol; hydrocarbon; carbon deposition;
- 【文献出处】 石油化工 ,Petrochemical Technology , 编辑部邮箱 ,2017年03期
- 【分类号】TQ211
- 【被引频次】4
- 【下载频次】154