High-Dispersed V2O5-CuOX Nanoparticles on h-BN in NH3-SCR and NH3-SCO Performance

Abstract

Typically, to meet emission regulations, the selective catalytic reduction of NOX with NH3 (NH3-SCR) technology cause NH3 emissions owing to high NH3/NOX ratios to meet emission regulations. In this study, V-Cu/BN-Ti was used to remove residual NOX and NH3. Catalysts were evaluated for selective catalytic oxidation of NH3 (NH3-SCO) in the NH3-SCR reaction at 200–300 °C. The addition of vanadium and copper increased the number of Brønsted and Lewis acid sites available for the reaction by increasing the ratio of V5+ and forming Cu+ species, respectively. Furthermore, h-BN was dispersed in the catalyst to improve the content of vanadium and copper species on the surface. NH3 and NOX conversion were 98% and 91% at 260 °C, respectively. Consequently, slipped NH3 (NH3-Slip) emitted only 2% of the injected ammonia. Under SO2 conditions, based on the NH3 oxidation reaction, catalytic deactivation was improved by addition of h-BN. This study suggests that h-BN is a potential catalyst that can help remove residual NOX and meet NH3 emission regulations when placed at the bottom of the SCR catalyst layer in coal-fired power plants.

Flexible Ti Mesh-Supported MnOx–CuOx/TiO2 Nanosheet Monolithic Catalysts for Low-Temperature Selective Catalytic Reduction of NOx with NH3

“…As shown in Figure b, the representative fitted Mn 2p 3/2 peaks, located at 640.8, 642.1, and 643 eV, correspond to Mn 2+ , Mn 3+ , and Mn 4+ , respectively . Correspondingly, the fitted Cu 2p 3/2 peaks at 933.0 and 934.7 eV are attributed to Cu +/0 and Cu 2+ , respectively (Figure c) . The O 1s spectra in Figure d could be fitted into surface absorbed oxygen (O α ) and lattice oxygen (O β ) at 530 and 531.7 eV, respectively .…”

“…34 Correspondingly, the fitted Cu 2p 3/2 peaks at 933.0 and 934.7 eV are attributed to Cu +/0 and Cu 2+ , respectively (Figure 6c). 35 The O 1s spectra in Figure 6d could be fitted into surface absorbed oxygen (O α ) and lattice oxygen (O β ) at 530 and 531.7 eV, respectively. 30 Furthermore, the proportions of Mn 4+ , Mn 3+ , Mn 2+ , Cu +/0 , Cu 2+ , and O α and O β are quantitatively evaluated by calculating the area ratios of corresponding fitted peaks.…”

Mechanism of ammonium bisulfate deposition on V1M5/Ti catalysts with synergistic effects of V and M (M = Ce, Co, Fe, and Mn) in low-temperature NH3-SCR

“…The disappearance of NH 3 on Lewis acid sites is due to the desorption of NH 3 by the N 2 and O 2 purging or the oxidation of NH 3 by O 2 . 51,52 The intensity of various sulfate peaks is higher than that of sulfite peaks in the absence of O 2 , indicating that the lattice oxygen provides a high activity on oxidation followed by ammoniation. It can be inferred that the oxidation followed by the ammoniation pathway is more dominant than the ammoniation followed by the oxidation pathway in the presence of O 2 with the cooxidation of SO 2 by O 2 and lattice oxygen.…”

The Effect of Nb/Mo on the Microstructures and Mechanical Properties of Fe–Mn–Al–Ni–C Austenitic Steels

“…[ 12–17 ] It was also shown that the size, distribution, and morphology of B2 phase had a remarkable impact on the mechanical properties. [ 18–25 ] For example, the dish‐like B2 particles formed during annealing at 900 °C in a Fe–15Mn–10Al–5Ni–0.8C steel led to an enhancement of ≈200 MPa in yield strength without a decrease in ductility compared with the B2 stringer bands formed at 700 °C. [ 20 ] The B2 band‐free Fe–16Mn–8Al–5Ni–1C steel possessed a better formability without any degradation of yield strength compared to the B2 banded Fe–15Mn–10Al–5Ni–0.8C steel, despite a much lower volume fraction of B2 in the former than the latter.…”