Transition metal ions (TMIs) hosted in zeolites have potential for generating highly active and selective catalysts. The speciation of metal ions inside the microporous zeolite pore system, including geometric constraints and anchoring points, grouping, and nuclearity of species, is not well understood. Determination of the location and structure of active sites is challenging because different species co-exist in the same zeolite, and complexity is added by their dynamics under reaction conditions. Three parameters are influential on the speciation of active TMIs in zeolites: (1) zeolite properties, including framework structure, composition, and metal loadings; (2) mobility of TMI species inside the zeolite micropores; and (3) influence of other inorganic species present in the reaction spaces. In our view, molecular-level understanding of metal-ion-exchanged zeolite catalysts requires a set of characterization and computational techniques that should go hand in hand with refined synthetic methods selectively generating active species.

中文翻译：

---

通过了解沸石中过渡金属离子种类的活性来释放伪分子催化剂的潜力


沸石中承载的过渡金属离子 （TMI） 具有产生高活性和选择性催化剂的潜力。微孔沸石孔隙系统内金属离子的形态，包括几何约束和锚定点、分组和物种的核性，尚不清楚。确定活性位点的位置和结构具有挑战性，因为不同的物质共存于同一沸石中，并且在反应条件下它们的动力学增加了复杂性。三个参数会影响沸石中活性 TMI 的形态：（1） 沸石特性，包括框架结构、成分和金属负载;（2） 分子筛微孔内 TMI 物种的迁移率;（3） 反应空间中存在的其他无机物质的影响。在我们看来，对金属离子交换沸石催化剂的分子水平理解需要一套表征和计算技术，这些技术应该与选择性生成活性物质的精细合成方法齐头并进。