Co-templated synthesis of zeolites for applications in adsorption and catalysis

沸石是微孔铝硅酸盐，应用于气体吸附和催化，使用无机或有机阳离子以指导或模板骨架结晶的水热方法制备。该项目旨在开发共模板化方法，其中无机阳离子和有机阳离子一起用于制备具有新结构或组成的沸石。这项工作将包括表征一系列柔性(Rho类型)沸石，这些沸石使用不同的金属和四乙基铵阳离子制备，显示出高度选择性的气体吸附。利用由此得出的原理，其他沸石合成将使用阳离子和其他小有机物的组合来设计，以获得在气体分离中有价值的小孔低Si/Al沸石，包括丝光沸石和正磷矿。这些结构将在气体分离过程中进行现场测量。埃利奥特·布鲁斯作为今年毕业的最佳MChem学生，在执行这些复杂的分析方面处于独特的地位。现有的现场同步辐射X射线粉末衍射数据是关于复杂的Rho家族结构ZSM-25和PST-20的，在吸附和不吸附二氧化碳的情况下，初步的结构研究将涉及到使用TOPAS程序对其进行精炼，这是此类复杂结构所需的。这将使阳离子位置的确定成为可能，因此结合计算研究，有助于理解它们对一系列工业相关分离的选择性吸附行为。此外，对于已被发现对工业分离感兴趣的混合阳离子体系，将进一步收集关于沸石Rho本身的X射线和中子衍射数据。此外，还将设计出稳定的汽车尾气催化剂所需的高Si/Al沸石的共模板化路线。使用非常昂贵的有机模板已经制备了几种有前景的材料。在这里，目的是使用无机模板和价格较低的有机模板的组合，使这种催化剂更容易获得，利用计算模型进行模板设计。强生马泰对此非常感兴趣，因此该项目将与他们合作进行，使埃利奥特能够深入了解工业催化化学，并访问他们在比林厄姆的广泛设施。

Zeolites are microporous aluminosilicates with applications in gas adsorption and catalysis, prepared hydrothermally using inorganic or organic cations to direct or template the framework crystallisation. This project aims to develop co-templating routes in which inorganic and organic cations are used together to prepare zeolites with new structures or compositions. The work will include the characterisation of a series of flexible (RHO-type) zeolites, prepared using different metal and tetraethylammonium cations that show highly selective gas adsorption. Using the principles derived from this, other zeolite syntheses will then be devised using combinations of cations and other small organics to give small pore low Si/Al zeolites valuable in gas separations, including merlinoite and phillipsite.The structures will be measured in situ during gas separations. Elliott Bruce, as the best MChem student graduating this year, is uniquely placed to perform these complex analyses. Existing in situ synchrotron X-ray powder diffraction data is available on the complex RHO family structures ZSM-25 and PST-20 with and without adsorbed carbon dioxide and initial structural studies will involve their refinement using the TOPAS program, required for such complex structures. This will enable the determination of cation locations and so help understand, in combination with computational studies, their selective adsorption behaviour for a range of industrially relevant separations. Additionally, further X-ray and neutron diffraction data will be collected on zeolite Rho itself, for mixed cation systems that have been found to be of interest for industrial separations with a collaborating industrial company.Further, co-templating routes to zeolites with high Si/Al required for stable auto-exhaust catalysts will be devised. Several promising materials have been prepared using highly expensive organic templates. Here, the aim is to use combinations of inorganic and less-expensive organic templates to make such catalysts more accessible, making use of computational modelling for template design. This is of great interest to Johnson Matthey, so the project will be conducted in collaboration with them, giving Elliott insight into industrial catalytic chemistry and access to their extensive facilities at Billingham.