The Assembly‐Disassembly‐Organization‐Reassembly Mechanism for 3D‐2D‐3D Transformation of Germanosilicate IWW Zeolite

Hydrolysis of germanosilicate zeolites with the IWW structure shows two different outcomes depending on the composition of the starting materials. Ge‐rich IWW (Si/Ge=3.1) is disassembled into a layered material (IPC‐5P), which can be reassembled into an almost pure silica IWW on treatment with diethoxydimethylsilane. Ge‐poor IWW (Si/Ge=6.4) is not completely disassembled on hydrolysis, but retains some 3D connectivity. This structure can be reassembled into IWW by incorporation of Al to fill the defects left when the Ge is removed.     

Zeolites with Continuously Tuneable Porosity

Zeolites are important materials whose utility in industry depends on the nature of their porous structure. Control over microporosity is therefore a vitally important target. Unfortunately, traditional methods for controlling porosity, in particular the use of organic structure‐directing agents, are relatively coarse and provide almost no opportunity to tune the porosity as required. Here we show how zeolites with a continuously tuneable surface area and micropore volume over a wide range can be prepared. This means that a particular surface area or micropore volume can be precisely tuned. The range of porosity we can target covers the whole range of useful zeolite porosity: from small pores consisting of 8‐rings all the way to extra‐large pores consisting of 14‐rings.     

Understanding the synthesis and reactivity of ADORable zeolites using NMR spectroscopy

Zeolites remain one of the most important classes of industrial catalysts used today, and with the urgent drive for the transition from petrochemical to renewable feedstocks, there is a renewed interest in developing new types of zeolite. Recent synthetic advances in the field have included the development of the assembly-disassembly-organisation-reassembly (ADOR) method. In this short review, we will discuss how solid-state NMR experiments can be used to probe the mechanism of the process by characterising the structure of the intermediates and products, show how ¹⁷O NMR spectroscopy can be used to probe the reactivity of ADORable zeolites and explain how this, in turn, can lead to fundamental questions of how zeolites behave in the presence of liquid water.     

Expansion of the ADOR Strategy for the Synthesis of Zeolites: The Synthesis of IPC‐12 from Zeolite UOV

The assembly–disassembly–organization–reassembly (ADOR) process has been used to disassemble a parent zeolite with the UOV structure type and then reassemble the resulting layers into a novel structure, IPC‐12. The structure of the material has previously been predicted computationally and confirmed in our experiments using X‐ray diffraction and atomic resolution STEM‐HAADF electron microscopy. This is the first successful application of the ADOR process to a material with porous layers.     

Synthesis and Post-Synthesis Transformation of Germanosilicate Zeolites

Zeolites are one of the most important heterogeneous catalysts, with a high number of large-scale industrial applications. While the synthesis of new zeolites remain rather limited, introduction of germanium has substantially increased our ability to not only direct the synthesis of zeolites but also to convert them into new materials post-synthetically. The smaller Ge-O-Ge angles (vs. Si-O-Si) and lability of the Ge−O bonds in aqueous solutions account for this behaviour. This Minireview discusses critical aspects of germanosilicate synthesis and their post-synthesis transformations to porous materials.     

超大孔分子筛,十年再回顾

沸石分子筛是一类重要的具有明确孔道结构以及催化位点的结晶孔材料. 但是由于其微孔开口的本质限制了其在大分子吸附与转化方面的应用. 10年前, 西班牙ITQ研究所的Corma教授、 吉林大学于吉红教授以及本文通讯作者发表了一篇关于超大孔分子筛的历史回顾文章. 该文从超大孔分子筛的合成、 结构、 假想结构以及催化性能等方面进行了综述. 这一类材料填补了传统沸石分子筛和有序介孔材料之间的孔径缺口. 在最近10年中, 多种新型超大孔分子筛以及新颖的合成方法陆续被报道. 本文对该方向近10年中的研究进行了综合评述.