Evaluation of the synthetic methods for preparing metal organic frameworks with transition metals

Abstract

In this study, preparation of metal-organic frameworks (Cu3BTC2, Fe3BTC2, Ni3BTC2 and Co3BTC2) (BTC = benzene-1,3,5-tricarboxylate) was performed by five different synthetic methods (solvothermal under autoclave, reflux, domestic microwave, ultrasonic, and mechanochemical conditions) and the results were compared in order to evaluate the advantages and disadvantages of each method with a focus on the domestic microwave method. All the results showed correlations between the reaction conditions and the yield, morphology, crystalline phases, and specific surface area. Characterization of the samples was performed by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and physisorption analysis. Experimental results have shown that the conventional method is a good choice for the preparation of M-BTCs, but it takes a long time and requires high temperature. With this work, we show that the domestic microwave is the best choice because it promotes the same MOF structures in a shorter time while achieving high purity, high specific area, and good quantitative yield. Notably, these transition metal-BTCs are promising candidates to be applied as catalysts in further studies.

Keywords

• metal-organic frameworks
• synthetic methods
• domestic microwave
• autoclave
• transitions metal