Highly dispersed MnO_x nanoparticles supported on three-dimensionally ordered macroporous carbon: a novel nanocomposite for catalytic reduction of NO_x with NH₃ at low temperature

Abstract

In this paper, we report a novel nanocomposite of MnO x nanoparticles supported by three-dimensionally ordered macroporous carbon (MnO x /3DOMC) fabricated by means of a simple multi-component infiltration of three-dimensional templates and its use as a catalyst for low-temperature selective catalytic reduction (SCR) of NO x with NH 3 . Several techniques, including scanning electron microscopy, X-ray diffraction, N 2 -sorption, transmission electron microscopy, X-ray photoelectron spectroscopy, NH 3 temperature-programmed desorption, and H 2 temperature-programmed reduction, are employed to characterize the MnO x /3DOMC nanocomposite. The results demonstrate that MnO x /3DOMC possesses a highly ordered macroporous structure with hierarchical mesopores in the walls of the macroporous skeleton. MnO x nanoparticles of 2-4 nm are observed to be highly dispersed on the 3DOM carbon scaffold. Compared with the MnO x /NAC and MnO x /TiO 2 catalysts prepared by a conventional impregnation method, the MnO x /3DOMC catalyst exhibits better low-temperature NH 3 -SCR activity, stability, and water vapor and/or SO 2 resistance ability. Such material represents a promising exploratory direction for enhancing the catalytic performance of metal oxide-based NH 3 -SCR catalysts.

Morphology-Dependent Catalytic Performance of NbOx/CeO2 Catalysts for Selective Catalytic Reduction of NOx with NH3

“…The O 1s spectra obtained on Nb/CeO 2 samples are exhibited in Figure C. The peaks at 529.5–530.0 and 531.7–532.7 eV could be attributed to lattice oxygen O 2– (denoted as O β ) and surface-adsorbed oxygen (denoted as O α ), respectively. , In oxidation reactions, O α , with higher mobility, is more reactive than O β . − Therefore, a high O α ratio could favor the oxidation of NO to NO 2 and then contribute to the fast SCR reaction. The relative surface concentration ratios of O α /O all on Nb/CeO 2 catalysts were determined from the corresponding peak areas and are listed in Figure C.…”

Sulfur and Water Resistance of Mn-Based Catalysts for Low-Temperature Selective Catalytic Reduction of NOx: A Review

“…Gao et al reported a novel nanocomposite of MnO x nanoparticles supported on three-dimensionally ordered macroporous carbon (MnO x /3DOMC). They found that this novel catalyst exhibited good water and sulfur tolerance ( Figure 32) [54]. As a special ordered carbon material with unique nanostructure and electronic properties, carbon nanotubes (CNTs) have been reported to be an interesting support for SCR catalysts [98,99].…”

Enhanced Catalytic Performance of Hierarchical MnOx/ZSM-5 Catalyst for the Low-Temperature NH3-SCR

“…In recent years, catalysts with hierarchical pore structures have attracted much attention for environmental catalytic applications. Due to their adjustable pore sizes and unique structural properties, Gao et al [10] demonstrated manganese oxide nanoparticles with a hierarchical mesopore structure in the walls of the macroporous skeleton supported by three-dimensionally ordered macroporous carbon, which exhibited better low-temperature NH 3 -SCR reaction activity, stability, as well as H 2 O and SO 2 resistance. Fang et al [11] prepared foam-like Fe 2 O 3 @CuO x monolith catalysts with a three-dimensional hierarchical structure and displayed a higher activity, stability, as well as SO 2 and H 2 O resistance than the catalyst without Fe 2 O 3 .…”