【摘要】 在前文研究天然Stilbite沸石(CXN沸石)水热稳定性影响因素的基础上,以27Al与29Si MAS NMR,NH3-TPD和低温氮吸附等详细研究了铵型CXN沸石骨架铝配位状态和硅配位状态,表面酸性与孔性质等与水蒸汽处理温度的关系.随温度升高,沸石骨架硅铝比逐渐提高,并伴随硅羟基缺陷增多.经750℃水蒸汽处理3 h后沸石骨架硅铝比可达到21.3.沸石总酸量随水蒸汽处理温度的提高而降低,沸石骨架铝脱除造成沸石孔道部分被堵塞,但同时形成有利于分子扩散的介孔.更多还原

【Abstract】 Based on the investigation of factors influencing the hydrothermal stability of natural Stilbite (CXN)zeolite,the relationship between the steaming temperature and coordinations of Al and Si in the framework of NH4-CXN zeolite has been investigated in detail by 27 Al& 29 Si MAS NMR characterizations, which indicate that both the framework SiO2/Al2O3 ratios and Si(OH)contents of the zeolite increase with the steaming temperature rising,and 21.3 of the framework SiO2/Al2O3 ratio for the zeolite was obtained by steam treatment at 750℃for 3 h.NH3-TPD shows that the total acid amount of the zeolite decreases with the steaming temperature rising.Nitrogen adsorption data prove that non-framework aluminum obviously blocks part of the zeolite channels and some mesopores appear at the same time.更多还原