The effect of CNTs on V-Ce/TiO2 for low-temperature selective catalytic reduction of NO

Carbon nanotubes (CNTs) are widely utilized as catalyst promoters because of their unique structure and electrical properties. In this study, CNTs were added as a promoter to V-Ce/TiO2 (VCT), which is a commercial catalyst used for the NH3-SCR reaction. We investigated the role of CNTs in the V-Ce/TiO2-CNTs (VCTC) catalyst. Therefore, we characterized them using X-ray diffraction (XRD), N-2 adsorption/desorption experiments, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), temperature-programmed reduction of H-2 (H-2-TPR), temperature-programmed desorption of NO/NH3 (NO/NH3-TPD), X-ray photoelectron spectroscopy (XPS), and in situ Fourier transform infrared spectroscopy (FT-IR). Higher NO conversion and N-2 selectivity were achieved in the VCTC catalyst than in the VCT catalyst, confirming the favorable effect of CNTs on the NH3-SCR reaction. Additionally, CNTs considerably influenced the crystal structure formation of the metal oxides located on the catalyst surface. Consequently, metal-metal and metal-support undergo distinct interactions, thereby positively influencing catalytic characteristics such as redox properties, oxidation state, acid sites, and the formation of nitrate species.