干湿循环中水对13X分子筛机械强度劣化和晶格畸变  

Mechanical strength deterioration and lattice distortion of 13X molecular sieve by water in dry-wet cycle

作　　者：张旭强[1] 吕功煊[1] 钱玲[1] 吴玉琪[1] 陈港泉[2] ZHANG Xu-qiang;LU Gong-xuan;QIAN Ling;WU Yu-qi;CHEN Gang-quan(State Key Laboratory for Oxo Synthesis and Selective Oxidation,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Dunhuang Academy,Institute of Conservation,Dunhuang 736200,China)

机构地区：[1]中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室,甘肃兰州730000 [2]敦煌研究院保护研究所,甘肃敦煌736200

出　　处：《化学研究与应用》2022年第1期126-133,共8页Chemical Research and Application

基　　金：国家自然科学基金重点项目(51732008)资助;甘肃省自然科学基金创新基地和人才计划项目(20JR5RA565)资助。

摘　　要：本文选用化工过程中常用的13X分子筛为模型,详细研究了在不同湿度下以及在干湿循环后分子筛机械强度的变化,发现经历干湿循环后分子筛的强度明显下降。经过干湿循环处理后的分子筛结构分析和表征结果显示,13X分子筛X射线衍射特征峰向高角度发生较显著的位移,这种位移与强度劣化有明显的正相关。干湿循环后分子筛的吸附-脱附特征也发生明显变化,对应的红外、核磁等表征结果也与强度下降、吸脱附特征变化、结构畸变有明显的对应关系。本文的结果表明,干湿循环过程中水分子可能诱发了13X分子筛晶格畸变,导致或者诱导了分子筛体相晶格有序度破坏,致使其机械强度大幅度降低。本文的结果对于改进分子筛载体的强度和理解分子筛载体失效有一定的指导意义。Herein,13X molecular sieve,which is commonly used in the chemical process,is selected as a model to study the mechanical strength change under different humidity and dry-wet cycle.We find that the strength of molecular sieve has decreased significantly after the dry-wet cycle.The results of structure analysis and characterization after dry-wet cycle treatment show that the XRD characteristic diffraction peaks of 13X molecular sieve have significantly shifted to the high angle,and these displacement have significant positive correlation with the strength deterioration.The adsorption-desorption characteristics of the molecular sieve also change obviously after the dry-wet cycle,and the corresponding infrared spectroscopy and solid state nuclear magnetic resonance spectra results also have similar corresponding relationship with the strength decrease.The gained results in the paper illustrate that the water molecules may induce the lattice distortion of 13X molecular sieve during the dry-wet cycle,which leads to the lattice order degree destruction in the bulk phase of the molecular sieve,resulting in a significant decrease in its mechanical strength.The results of this paper have a certain guiding significance for improving strength and understanding failure of molecular sieve carriers.

关 键 词：13X分子筛 机械强度劣化 晶格畸变 干湿循环 水分子 

分 类 号：O643.36[理学—物理化学]