In Situ Thermal Solvent-Free Synthesis of Zeolitic Imidazolate Frameworks with High Crystallinity and Porosity for Effective Adsorption and Catalytic Applications

A facile and eco-friendly in situ thermal (IST) method was developed to synthesize zeolitic imidazole frameworks based on a 2-methylimidazole (2-MIM) linker (ZIF-67, ZIF-8, and Zn/Co-ZIF). A single-step and a short processing time with the lowest precursor ratio (M/L) and solvent-free provided an advantage of the IST method over the reported traditional synthesis procedures. A variety of synthesis parameters, including temperature, time, precursor, and gas atmosphere, were optimized to obtain excellent crystalline and porosity properties. In the following, different characterization techniques were comprehensively applied to verify the properties of the synthesized materials. Moreover, the beneficial chemical and physical properties of the synthesized material exhibited potential application for adsorption and catalysis. Overall, the IST method approach is a novel ZIF synthesis procedure generating high porous crystalline ZIFs. The IST is a green strategy avoiding solvent, activation, or post-treatment to remove unreacted residual, side-product, and guest molecules from the product. Additionally, the single-step IST process showed scalability for large-scale material synthesis.