Effect of -COOH in organic linkers on the hydrochlorination performance of SnMOF-based catalysts

A series of tin-organic frameworks materials (SnMOF) were synthesized using different organic linkers, including phthalic acid, isophthalic acid, 1,4-dicarboxybenzene, and 1,3,5-benzenetricarboxylic acid. The structure and morphology of SnMOF were characterized by Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction, N-2 adsorption/desorption isortherm (BET), scanning electron microscope-Energy Dispersive System (EDS), and Thermogravimetry (TG). Taking together, these experimental results indicated that the different types and amounts of -COOH in organic linkers have a significant effect on the physical properties of SnMOF. Among them, carbon-supported SnMOF as catalysts for acetylene hydrochlorination features the considerable activity and vinyl chloride selectivity. Such excellent performance is attributed to the fact that 1,3,5-benzenetricarboxylic acid can effectively strengthen the interaction effect between C2H2 and Sn-O-C, according to the results of C2H2-TPD, HCl adsorption experiments, and X-ray photoelectron spectroscopy (XPS).