Catalytic oxidation of toluene by metal phthalocyanine loaded on cordierite honeycomb

Abstract

BACKGROUND As one of the common VOCs, toluene is not only hazardous to human health, leading to respiratory disease, cancers, but also harmful to the environment, causing destruction of the ozone layer, photochemical smog and global warming. Catalytic oxidation is one of the most advanced technologies for eliminating VOCs and can convert VOCs to benign components such as carbon dioxide (CO2) and water. As catalysts are important in the catalytic process, finding highly active, low cost catalysts is critical. Metal phthalocyanine(MPc) has potential practical value and wide application prospects as catalysts for its uniquely high catalytic activity and selectivity. Thus, four monolithic catalysts were prepared by impregnating MPc onto cordierite honeycomb. RESULTS Characterization by scanning electron microscopy, X‐ray diffraction, Fourier transform infrared and energy‐dispersive X‐ray spectroscopy showed that the metal phthalocyanines were successfully loaded on the cordierite honeycomb. A fixed‐bed reactor was used to examine the catalytic oxidation effects of metal phthalocyanine species, catalyst amount, feed concentration, feed flow and temperature on toluene. The result showed that the catalytic activity of phthalocyanine iron (FePc) to toluene was better than other three MPcs. The optimal reaction conditions were 120 mg catalyst, 6.3 × 10−3 mol m−3feed concentration and 250 mL min−1 feed flow. The conversion of toluene increased with increasing temperature. CONCLUSION FePc/C also had a good catalytic oxidation effect on different aromatic hydrocarbon compounds (benzene and 1,4‐dimethyl‐benzene). The oxidation products of the catalytic system were CO2 and H2O, which met the requirements of green chemistry. FePc/C is a promising catalytic material because it has high catalytic activity and can be operated in simple conditions, such as low temperatures. © 2022 Society of Chemical Industry (SCI).