A Cu/Al-MCM-41 mesoporous molecular sieve: application in the abatement of NO in exhaust gases



Título del documento: A Cu/Al-MCM-41 mesoporous molecular sieve: application in the abatement of NO in exhaust gases
Revista: Brazilian journal of chemical engineering
Base de datos: PERIÓDICA
Número de sistema: 000309002
ISSN: 0104-6632
Autores: 1
2

Instituciones: 1Universidade Federal de Sao Carlos, Departamento de Engenharia Quimica, Sao Carlos, Sao Paulo. Brasil
2Centro Universitario do Sul de Minas, Laboratorio de Catalise e Desenvolvimento de Materiais, Varginha, Minas Gerais. Brasil
Año:
Periodo: Sep
Volumen: 22
Número: 3
Paginación: 433-442
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental
Resumen en inglés Propane oxidation and reduction of NO to N2 with propane under oxidative conditions on a Cu-Al-MCM-41 mesoporous molecular sieve and Cu-ZSM-5 zeolites were studied. Both types of catalysts were prepared by ion exchange in aqueous solutions of copper acetate and characterised by X-ray diffraction (XRD), nitrogen sorption measurement, diffuse reflectance ultra-violet spectroscopy (DRS-UV), diffuse reflectance infra-red Fourier transform spectroscopy (DRIFTS) of the adsorption of CO on Cu+ and temperature-programmed reduction with hydrogen (H2-TPR). The NO reduction was performed between 200 and 500 ºC using a GHSV = 42,000 h-1. H2-TPR data showed that in the prepared Cu-Al-MCM-41 all the Cu atoms are on the surface of the mesopores as highly dispersed CuO, which results in a decrease in specific surface area and in mesopore volume. H2-TPR together with DRIFTS data provided evidence that in Cu/ZSM-5 catalysts, Cu atoms are found as two different Cu2+ cations: Cualpha2+ and Cubeta2+, which are located on charge compensation sites, and their thermo-redox properties were different from those of Cu atoms in Cu-Al-MCM-41. The specific activity of the Cu2+ exchangeable cations in Cu-ZSM-5, irrespective of their nature, was much greater than that of the Cu2+ in Cu-Al-MCM-41, where they are found as CuO
Disciplinas: Química
Palabras clave: Ingeniería química,
Catálisis,
Tamices moleculares,
Propano,
Oxidación,
Oxido nitroso,
Reducción,
Zeolitas
Keyword: Chemistry,
Chemical engineering,
Catalysis,
Molecular sieves,
Propane,
Oxidation,
Nitrous oxide,
Reduction,
Zeolites
Texto completo: Texto completo (Ver HTML)