1.1 本试验方法涵盖了使用沸石X射线衍射图中选定的峰测定ZSM-5沸石相对结晶度的程序。 1.2 该测试方法提供了一个数字，即样品ZSM-5的一部分XRD图案的强度与参考ZSM-5图案的相应部分的强度之比。强度比以百分比表示，然后标记为XRD相对结晶度百分比/ZSM-5。这种比较通常用于沸石技术，通常称为结晶度百分比。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 ZSM-5是一种可与SiO结晶的硅质沸石 2. /铝 2. O 3. 比率在20到1000之间。ZSM-5在后结晶步骤中改性为H-阳离子形式（HZSM-5），自20世纪70年代以来一直被用作形状选择性酸位催化剂，用于石油精炼和石化产品生产，包括烷基化、异构化、流体裂化催化（FCC）和甲醇制汽油等过程。ZSM-5家族中最含硅的一员，有时被称为硅分子筛，具有疏水性，用于从含水系统中选择性吸附有机分子。 4.2 该X射线程序旨在报告制造ZSM时的相对结晶度- 5.相对结晶度/ZSM-5数在技术、研究和规范中证明是有用的。 4.3 综合峰面积法（程序A）优于峰高法（程序B），因为它将XRD强度计算为多个峰的总和，而不是仅利用一个峰。ZSM-5分子筛晶胞内电子密度分布的变化可能导致ZSM-5分子筛XRD图谱中单个峰强度的剧烈变化。电子密度分布取决于以下因素: 4.3.1 客体分子填充孔隙的程度和这些客体分子的性质。 4.3.2 阳离子的类型及其存在程度（这些阳离子也可能影响ZSM-5样品对X射线的吸收）。 4.3.3 在这种XRD方法中，客体分子H 2. O完成孔隙填充。还可能存在其他客体分子类型，包括众多胺、二胺和季铵阳离子中的一种，它们可以作为ZSM-5结构结晶的模板。 4.3.4 由于上述因素 4.3.1 到 4.3.3 这可能会改变ZSM-5中XRD峰的强度，这种XRD方法将在参考ZSM时提供最佳的相对结晶度测定- 5和样品ZSM-5具有相似的制备和组成历史。 4.4 ZSM-5可以正交或单斜对称存在，这取决于前体凝胶的组成或结晶后改性条件，或两者兼有。在正交类型中，以23.1和23.8°2θ为中心的XRD峰通常分裂为双峰，而不太对称的单斜类型可能显示这些峰进一步分裂为三峰。这些峰的峰面积强度不受晶体形态的影响。正交晶型在24.3°2θ处的XRD峰是单线态，因此最适合峰高法（程序B）。 如果24.3°峰被拆分（单斜形式的双峰），则应使用积分峰面积法（程序A）。 4.5 如果样品中存在ZSM-5以外的晶相，其衍射峰可能与为综合峰面积法（程序A）选择的一些ZSM-5峰重叠。如果有理由怀疑存在此类成分，则应选择峰高法（程序B）进行分析，前提是不干扰用于计算的24.3°2θ峰。

1.1 This test method covers a procedure for determination of the relative crystallinity of zeolite ZSM-5 using selected peaks from the X-ray diffraction pattern of the zeolite. 1.2 The test method provides a number that is the ratio of intensity of a portion of the XRD pattern of the sample ZSM-5 to intensity of the corresponding portion of the pattern of a reference ZSM-5. The intensity ratio, expressed as a percentage, is then labeled percent XRD relative crystallinity/ZSM-5. This type of comparison is commonly used in zeolite technology and is often referred to as percent crystallinity. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 ZSM-5 is a siliceous zeolite that can be crystallized with SiO 2 /Al 2 O 3 ratio in the range of 20 to greater than 1000. ZSM-5, upon modification to the H-cation form (HZSM-5) in a post-crystallization step, has been used since the 1970s as a shape selective, acid-site catalyst for petroleum refining and petrochemicals production, including such processes as alkylation, isomerization, fluid cracking catalysis (FCC), and methanol-to-gasoline. The most siliceous member of the ZSM-5 family, sometimes called silicalite, is hydrophobic and it is used for selective sorption of organic molecules from water-containing systems. 4.2 This X-ray procedure is designed to allow a reporting of the relative degree of crystallization upon manufacture of ZSM-5. The relative crystallinity/ZSM-5 number has proven useful in technology, research, and specifications. 4.3 The Integrated Peak Area Method (Procedure A) is preferred over the Peak Height Method (Procedure B) since it calculates XRD intensity as a sum from several peaks rather than utilizing just one peak. Drastic changes in intensity of individual peaks in the XRD pattern of ZSM-5 can result from changes in distribution of electron density within the unit cell of the ZSM-5 zeolite. The electron density distribution is dependent upon the following factors: 4.3.1 Extent of filling of pores with guest molecules and the nature of these guest molecules. 4.3.2 Type of cations and extent of their presence (these cations may also affect the absorption of X rays by the ZSM-5 sample). 4.3.3 In this XRD method, the guest molecule H 2 O completes the filling of the pores. Other guest molecule types may also be present, including one of numerous amines, diamines, and quarternary ammonium cations that can function as a template for crystallization of the ZSM-5 structure. 4.3.4 Because of the factors mentioned in 4.3.1 to 4.3.3 that could vary the intensities of the XRD peaks in ZSM-5, this XRD method will provide the best determination of relative crystallinity when the reference ZSM-5 and sample ZSM-5 have a similar history of preparation and composition. 4.4 ZSM-5 can exist with either orthorhombic or monoclinic symmetry, depending upon the composition of the precursor gel or post-crystallization modification conditions, or both. In the orthorhombic type, the XRD peaks centered at about 23.1 and 23.8° 2θ are usually split into doublets, whereas the less symmetric monoclinic type may show a further split of these peaks into triplets. The peak area intensities of these peaks are unaffected by the crystalline form. The XRD peak at 24.3° 2θ for the orthorhombic form is a singlet and hence is the most suitable for the Peak Height Method (Procedure B). If the 24.3° peak is split (doublet in the monoclinic form), then the Integrated Peak Area Method (Procedure A) should be used. 4.5 If crystalline phases other than ZSM-5 are present in the sample, their diffraction peaks may overlap with some of the ZSM-5 peaks selected for the Integrated Peak Area Method (Procedure A). If there is reason to suspect the presence of such components, then the Peak Height Method (Procedure B) should be chosen for analysis provided that there is no interference with the 24.3° 2θ peak that is used for the calculation.