2026-05-27T05:23:46Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/267692026-02-03T10:56:27Zcom_10630_2254col_10630_37953

Comparison of Cu-CHA-zeolites in the hybrid NSR-SCR catalytic system for NOx abatement in mobile sources Molina-Ramírez, Sergio Cortés-Reyes, Marina Herrera-Delgado, María Concepción Larrubia-Vargas, María Ángeles Alemany-Arrebola, Luis José Catalizadores Motores diesel Aire -- Contaminación -- Control Control de la contaminación del aire DeNOx activity in a NSR–SCR hybrid system of two copper-containing chabazite-type zeolitic catalysts was addressed. A Pt-Ba-K/Al2O3 model catalyst was used as the NSR (NOx storage and reduction) catalyst. For the SCR (selective catalytic reduction) system, two Cu-CHA zeolites were synthesized employing a single hydrothermal synthesis method assisted with ultrasound and incorporating Cu in a 2 wt.%, 2Cu-SAPO-34 and 2Cu-SSZ-13. The prepared catalysts were characterized, and the crystallinity, surface area, pore size, HR-TEM and EDX mapping, coordination of Cu ions and acidity were compared. The NH3 storage capacity of the SCR catalysts was 1890 and 837 μmol NH3·g−1cat for 2Cu-SAPO-34 and 2Cu-SSZ-13, respectively. DeNOx activity was evaluated for the single NSR system and the double-bed NSR–SCR by employing alternating lean (3%O2) and rich (1%H2) cycles, maintaining a concentration of 600 ppm NO, 1.5% H2O and 0.3% CO2 between 200 and 350 °C. The addition of the SCR system downstream of the NSR catalyst significantly improved NOx conversion mainly at low temperature, maintaining the selectivity to N2 above 80% and reaching values above 90% at 250 °C when the 2Cu-SSZ-13 catalyst was located. The total reduction in the production of NH3 and ~2% of N2O was observed when comparing the NSR–SCR configuration with the single NSR catalyst. 2023-06-05T06:57:44Z 2023-06-05T06:57:44Z 2023-06-02 2023-03-10 journal article Molina-Ramírez S, Cortés-Reyes M, Herrera C, Larrubia MÁ, Alemany LJ. Comparison of Cu-CHA-Zeolites in the Hybrid NSR-SCR Catalytic System for NOx Abatement in Mobile Sources. Chemistry. 2023; 5(1):602-615. https://doi.org/10.3390/chemistry5010043 https://hdl.handle.net/10630/26769 10.3390/chemistry5010043 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI