Novel Porous Iron Molybdate Catalysts for Synthesis of Dimethoxymethane from Methanol: Metal Organic Frameworks as Precursors

Abstract

As a novel performance, methanol gas conversion to dimethoxymethane (DMM) in one-step based on Fe-Mo-O (iron molybdate mixed oxides) catalysts with high surface area fabricated by metal organic frameworks (MOFs) precursors was improved. For this approach, at first, Fe(III) precursors (iron (III) 1,3,5-benzenetricarboxylate (MIL-100 (Fe) and iron terephthalate (MOF-235)) and Mo(VI) precursor ((NH4)6Mo7O24·٤H2O) were synthesized. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) analysis, temperature programmed desorption (NH3-TPD), dynamic light scattering (DLS) technique, Brunauer–Emmett–Teller analysis (BET) and inductively coupled plasma optical emission spectroscopy (ICP-OES) techniques. Application of MOFs as precursors was provided fabricated catalysts with high specific surface area which subsequently afforded higher selectivity and productivity of dimethoxymethane. Novel catalytic performances can be due to synergistic effect between Mo(VI) and Fe(III) species which leads to catalysts with porous structure. As a result, with a Mo:Fe molar ratio of 3, the best catalyst was obtained which exhibited 43% conversion, 92% selectivity and 39% yield, respectively.