Synthesis and characterization metal–organic framework, ZIF-8 e ZIF-67

Abstract

Metal-organic frameworks( MOFs) also called coordination polymers represent a new class of inorganic-organic hybrid materials which are characterized by their high stability, high porosity and well-defined crystal structures. These materials have shown promising potential for numerous applications, including in catalysis which is highlighted because they can act as bifunctional catalysts assets. The advantages of using these catalysts on those already reported are features such as high surface area and controlling the character of acid-base sites (Lewis or Brönsted). Zeolitic imidazolate frameworks (ZIFs) is a subfamily of MOFs which has gained interest mainly for combine the advantages of the MOFs with high thermal and chemical stability of zeolites. The MOFs, and consequently the ZIFs can be synthesized in order to have both acid and basic sites. This specificity has great attractiveness, especially for reactions that may occur by mechanisms that require both sites, such as the production of biodiesel. This paper presents the synthesis of bifunctional heterogeneous catalysts, based on Metal-organic frameworks  with the preparation of ZIF-8 and ZIF-67 accomplished with their characterization by techniques of X-ray diffraction (XRD), nitrogen physisorption and Spectroscopy infrared (FTIR). The analysis of the obtained results shows high crystallinity, presence of characteristic functional groups of the catalysts and low values of textural properties. The observed data agree with the theoretical pattern observed in the background published studies suggesting the success of the performed syntheses.