Trivalent iron-tartaric acid metal-organic framework for catalytic ozonation of succinonitrile

As porous crystal materials, metal-organic frameworks (MOFs) have attracted wide attention in the field of environmental remediation. In this study, a trivalent iron-tartaric acid metal-organic framework (T2-MOF) was successfully synthesized using the inexpensive raw materials ferric chloride (FeCl₃.6H₂O) and tartaric acid (C₄H₆O₆). The physical and chemical properties of T2-MOF were studied by using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller. After that, T2-MOF was used as a catalyst for catalytic ozonation of succinonitrile. The results show that T2-MOF has obvious crystal characteristics and uniform structure. In addition, T2-MOF exhibits strong catalytic performance in ozonation of succinonitrile. The results indicate that the chemical oxygen demand (COD) removal rate is affected by various operating parameters including catalyst characteristics dosages and initial pH values. In the ozonation with 30 mg L^-1 T2-MOF, the COD removal rate of 100 mg L^-1 succinonitrile reached 73.1% (±4.6%) within 180 min, which was 67.3% (±4.4%) higher than that obtained in the process without catalyst. T2-MOF maintained strong catalytic performance with the pH range of 3.0-7.0. By monitoring the Fe²⁺ concentration at different reaction time, it was found that the homogeneous catalysis occurred simultaneously with the heterogeneous catalysis.