Optimizing the performance of catalytic traps for hydrocarbon abatement during the cold-start of a gasoline engine

• Published in: Journal of hazardous materials 2014-08, Vol.279, p.527-536
• Main Authors: Puértolas, B., Navlani-García, M., García, T., Navarro, M.V., Lozano-Castelló, D., Cazorla-Amorós, D.
• Format: Article
• Language: English
• Subjects: Air Pollutants - chemistry; Air Pollution - prevention & control; Applied sciences; Atmospheric pollution; Catalysis; CATALYSTS; Catalytic reactions; Catalytic traps; Chemical engineering; Chemistry; Cold-start emissions; Copper; Copper - chemistry; COPPER ACETATE; COPPER NITRATE; COPPER OXIDE; Copper oxides; Cu-ZSM-5; ENGINES; Exact sciences and technology; FABRICATION; Factorial design; Gasoline; General and physical chemistry; Hydrocarbons; Hydrocarbons - isolation & purification; Models, Statistical; Nanoparticles; OXIDES; PARTICLES; Pollution; Precursors; Reactors; Synthesis; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Vehicle Emissions - analysis; X-Ray Diffraction; Zeolites
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.07.042

•Optima synthesis conditions for hydrocarbon removal were determined by factorial design.•Improved hydrocarbon retention was achieved for highly exchanged copper zeolites.•CuO nanoparticles catalyzed the total oxidation of trapped hydrocarbons.•Copper acetate precursor favored higher dispersions of CuO nanoparticles.•Maximum propene removal efficiency from the optimization procedure was 93.9%. A key target to reduce current hydrocarbon emissions from vehicular exhaust is to improve their abatement under cold-start conditions. Herein, we demonstrate the potential of factorial analysis to design a highly efficient catalytic trap. The impact of the synthesis conditions on the preparation of copper-loaded ZSM-5 is clearly revealed by XRD, N2 sorption, FTIR, NH3-TPD, SEM and TEM. A high concentration of copper nitrate precursor in the synthesis improves the removal of hydrocarbons, providing both strong adsorption sites for hydrocarbon retention at low temperature and copper oxide nanoparticles for full hydrocarbon catalytic combustion at high temperature. The use of copper acetate precursor leads to a more homogeneous dispersion of copper oxide nanoparticles also providing enough catalytic sites for the total oxidation of hydrocarbons released from the adsorption sites, although lower copper loadings are achieved. Thus, synthesis conditions leading to high copper loadings jointly with highly dispersed copper oxide nanoparticles would result in an exceptional catalytic trap able to reach superior hydrocarbon abatement under highly demanding operational conditions.