This research is conducted to improve the dispersion of MnOx-CeO2 catalyst because manganese is easily aggregated during continuous thermal environment at operating temperature. Aggregated MnOx particles on the support can be a major reason to degrade the catalyst performance. Therefore, the improved dispersion of MnOx particles leads to the enhancement of the catalyst performance by utilizing hexagonal boron nitride (h-BN) which is well known as thermally stable material. Due to the dispersion of MnOx-CeO2 with 5-20 nm particle size, h-BN-supported MnOx-CeO2 catalyst shows the 93% efficiency in NOx removal at 200 °C. The structure and properties of MnOx-CeO2/h-BN catalyst are characterized by X-ray diffraction, Fourier transform infrared spectroscopy spectra, and NH3-temperature programmed desorption. Then, NOx removal efficiency of catalyst is evaluated on a fixed bed reactor and h-BN-supported catalyst, (Mn0.2-Ce0.1)/BN, increases NOx removal efficiency up to 20% at 200 °C in spite of 2/3 reduced content of MnOx-CeO2 compared to no-supported catalyst (Mn0.3-Ce0.15).
Keywords: Dispersion; Hexagonal boron nitride; Low temperature; NOx removal; Nano-sized; SCR catalyst.