Enhancing Water Tolerance and N 2 Selectivity in NH 3 -SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer.

Autor: Komaty S; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Andijani M; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Wang N; Physical Sciences and Engineering Division (PSE), Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia., Navarro de Miguel JC; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Kumar Veeranmaril S; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Hedhili MN; Core Laboratories, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia., Silva CIQ; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Wang Y; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Abou-Daher M; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia., Han Y; Physical Sciences and Engineering Division (PSE), Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia., Ruiz-Martinez J; Physical Sciences and Engineering Division (PSE), KAUST Catalysis Center (KCC), Catalysis Nanomaterials and Spectroscopy (CNS), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia.
Jazyk: angličtina
Zdroj: Environmental science & technology [Environ Sci Technol] 2024 Jul 31. Date of Electronic Publication: 2024 Jul 31.
DOI: 10.1021/acs.est.4c01585
Abstrakt: Mn-based catalysts are promising candidates for eliminating harmful nitrogen oxides (NO x ) via selective catalytic reduction with ammonia (NH 3 -SCR) due to their inherent strong redox abilities. However, poor water tolerance and low N 2 selectivity are still the main limitations for practical applications. Herein, we succeeded in preparing an active catalyst for NH 3 -SCR with improved water tolerance and N 2 selectivity based on protecting MnO x with a secondary growth of a hydrophobic silicalite-1. This protection suppressed catalyst deactivation by water adsorption. Interestingly, impregnating MnO x on MesoTS-1 followed by silicalite-1 protection allowed for a higher dispersion of MnO x species, thus increasing the concentration of acid sites. Consequently, the level of N 2 O formation is decreased. These improvements resulted in a broader operating temperature of NO x conversion and a modification of the NH 3 -SCR mechanism. Diffuse reflectance infrared Fourier transform spectroscopy analysis revealed that unprotected Mn/MesoTS-1 mainly followed the Eley-Rideal mechanism, while Mn/MesoTS-1@S1 followed both Langmuir-Hinshelwood and Eley-Rideal mechanisms.
Databáze: MEDLINE
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