Reactivation of a commercial diesel oxidation catalyst by acid washing.
The catalytic activity of samples taken from an oxidation catalyst mounted on diesel-driven automobiles and aged under road conditions was recovered to a significant extent by washing with a dilute solution of citric acid. The characterization of samples arising from a fresh, a vehicle-aged, and a regenerated catalyst was carried out by scanning electron microscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Relatively high levels of S and P, in the form of aluminum sulfate and phosphate, respectively, together with contaminant Si were detected in the used catalyst. Washing of the vehicle-aged catalytic oxidation converter revealed high efficiency in the extraction of the main contaminants detected (S and P) by this nondestructive methodology. The results of the experiments reported here should encourage the development of a technology based on this reactivation procedure for the rejuvenation of the catalytic device mounted on diesel exhaust pipes.
Galisteo
Francisco Cabello
FC
Instituto de Catálisis y Petroleoquímica (CSIC), Marie Curie 2, Campus de Cantoblanco, 28049-Madrid, Spain. fcgalisteo@icp.csic.es
Mariscal
Rafael
R
Granados
Manuel López
ML
Fierro
José Luis García
JL
Brettes
Pilar
P
Salas
Oscar
O
D000397:Air Pollution / Q000517:prevention & control; D000535:Aluminum / Q000032:analysis; D001336:Automobiles; D002384:Catalysis; D019343:Citric Acid / Q000737:chemistry*; D005742:Gasoline; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010758:Phosphorus / Q000032:analysis; D010984:Platinum / Q000032:analysis; D013057:Spectrum Analysis / Q000379:methods; D013455:Sulfur / Q000032:analysis; D001335:Vehicle Emissions; D014961:X-Ray Diffraction
D005742:Gasoline; D001335:Vehicle Emissions; D010758:Phosphorus; D019343:Citric Acid; D010984:Platinum; D013455:Sulfur; D000535:Aluminum