Selective Catalytic Reduction of NO With NH3 over High Purity Palygorskite-supported MnO2 with Different Crystal Structures

Abstract

In order to find efficient catalysts for low-temperature selective catalytic reduction with ammonia (NH 3 -SCR), several MnO 2 with different crystal structure have been supported on high-purity palygorskite (Pal) by a hydrothermal method. The effect of MnO 2 crystal structures on the NH 3 -SCR performance of the catalysts was investigated. All catalysts were characterized by X-ray diffraction (XRD), N 2 adsorption-desorption, Raman spectrum, Thermo gravimetric analysis/Differential thermo gravimetric (TG/DTG), ammonia-temperature programmed desorption (NH 3 -TPD), hydrogen-temperature programmed reduction (H 2 -TPR), Transmission electron microscope (TEM) and X-ray energy dispersive spectroscopy (EDS) and X-ray photoelectron spectrometer (XPS). The presented results suggested that α-MnO 2 /Pal catalyst exhibit the highest catalytic activity among four type MnO 2 /Pal catalysts in the temperature range of 50-400°C, own promising stability during a 24 h continuous denitration experiment. Furthermore, the crystal structure affords α-MnO 2 /Pal with the highest specific surface area and more acidic sites, which is beneficial for the SCR reaction. It has improved the NH 3 adsorption ability and catalytic activity of the catalyst.

Formation of inorganic liquid gallium particle–manganese oxide composites

“…The characteristic peaks associated with the MnO 2 product were identified at 502, 563 and 636 cm −1 for samples reacted for 40 min. 13,47,48 After annealing, the Ga 2 O 3 -related peaks can be seen at 414, 699 and 765 cm −1 , as the excessive Ga particles were oxidised during the annealing. [49][50][51] The peaks at 699 and 765 cm −1 were also detected in the unannealed pure Ga samples and were attributed to the oxide layer that forms natively on the surface of Ga. By introducing more KMnO 4 reagent into the reaction, the peak at 563 cm −1 gradually intensified with a positive correlation with the increase of the KMnO 4 concentration for both the unannealed and annealed samples.…”

Photodegradation of Nitrogen Oxide under Solar Light Using a Facile Synthesis Catalyst

“…When applying a high-quality catalytic, it is necessary to obtain better performance at low temperatures and to reduce application costs (B. Zhang, Chen, Liu, Zou, & Chen, 2020). Both conventional and developing catalysts, such as TiO2, ZnO, SnO2, Cu2O, Bi2S3, g-C3N4, Bi2WO6, and BiPO4, among others, are typically applied for the reduction of environmental pollutants, including NO (J.…”