Molecular sieve manufacturer explains the roles of cationic templates, co templates, and template free templates

The original intention of ion thermal synthesis was to simplify the template oriented process in traditional hydrothermal synthesis by combining solvents and templates. Template molecules typically influence the synthesis process of molecular sieves through the interaction between the positive charge carried by cations and the negative charge of the molecular sieve skeleton. The commonly used template ion structure is very similar to the structure of ionic liquids. Therefore, cations in ionic liquids can bind well to the framework of molecular sieves, and their binding method is completely the same as that in traditional zeolite molecular sieve synthesis.
Similarly, ionic liquids can also serve as both solvents and templates for the synthesis of metal organic frameworks. Most solvothermal prepared MOFs have a neutral skeleton structure, but when the template is a cation, the molecular sieve skeleton exhibits negative charge, which is similar to the traditional molecular sieve synthesis process. Of course, the overall goal of using templates is to achieve structural control of the material by changing the size of the template cation. Although the above is well-known, templates cannot achieve very precise control of the final product structure, except for their correlation with the size of cations. In this work, changing the size of ionic liquid cations has a certain impact on the structure of the final product. Due to the tendency of the skeleton structure to adapt to the template, larger cation templates will produce a more open skeleton structure. However, this is not a unique structure in the synthesis of MOF structures, indicating that the template only serves as a filler without template skeleton interaction.
So far, cations in ionic liquids have only served as templates in synthesis. However, just like any other solvent, including water, it is also possible to interact with the molecular sieve framework by binding. Most ionic liquids based on dialkyl imidazole cations do not connect to metal sites. However, some ionic liquids can break bonds and leave alkylated imidazole species under specific conditions, thereby coordinating with metals. Under hydrothermal synthesis conditions, controlling the interaction between solvents and skeleton materials plays a crucial role in determining the final performance of materials.
Of course, ionic liquids will only serve as solvents and not be enclosed in the final structure. For phosphorus aluminum molecular sieves and MOFs materials, if the ionic liquid used is a conventional template, it can be inferred that they will be enclosed in the final structure. However, in some cases, this phenomenon does not occur. The most important reason for this situation may be the hydrophobic effect of ionic liquids. In the synthesis process of phosphorus aluminum molecular sieves and MOFs materials, the stronger the hydrophobicity of ionic liquids, the harder it is to be enclosed in the structure of molecular sieves. Of course, if the chemical properties of the system change, the equilibrium relationship between the solvent and template of the ionic liquid will also change. Hunan Providence New Materials Co., Ltd is a professional molecular sieve manufacturer which can provide USY zeolite, NaY zeolite, REY zeolite, ZSM-5 zeolite, welcome to consult.