Catalytic performance of CuO/Ce_0.8Zr_0.2O₂ loaded onto SiC-DPF in NO_x-assisted combustion of diesel soot

Abstract

This work presents a comparative study between the catalytic performance of the 2% CuO/ceria-zirconia powder catalyst and the same catalyst supported on silicon carbide DPF (Diesel Particulate Filter) towards NO oxidation reaction and soot combustion reaction. The ceria-zirconia catalyst was prepared by the coprecipitation method and 2 wt% copper was incorporated by the incipient wetness impregnation method. The catalyst was incorporated onto the ceramic support using a simple and organic solvent-free procedure by a simply dipping the DPF into an aqueous solution of the catalyst. The powder catalyst has been characterized using N 2 adsorption at À196 C, XRD and Raman Spectroscopy; whereas the catalytic coating morphology has been evaluated by SEM and the mechanical stability by an adherence test. Both catalyst configurations were tested for NO oxidation to NO 2 and for soot combustion under NO x /O 2 .The results revealed that incorporation of the very active copper/ceria-zirconia catalyst onto SiC-DPF has been successfully achieved by a simple coating procedure. Furthermore, the catalytic coating has shown suitable mechanical, chemical and thermal stability. A satisfactory catalytic performance of the catalytic-coated filter was reached towards the NO oxidation reaction. Moreover, it was proved that the catalytic coating is stable and the corresponding coated DPF can be reused for several cycles of NO oxidation without a significant decrease in its activity. Finally, it was verified that the loose-contact mode is a good choice to simulate the catalytic performance of this active phase in a real diesel particulate filter.

The Issue of Soot-Catalyst Contact in Regeneration of Catalytic Diesel Particulate Filters: A Critical Review

“…Quiles-Díaz et al [31] deposited a nano-sized 2% CuO/ceria-zirconia catalyst on SiC DPFs using a simple and organic solvent-free procedure. The filter was simply dipped into an aqueous solution of the catalyst.…”

“…Quiles-Díaz et al [31] investigated the effect of different soot loads (at an assigned catalyst load) on the regeneration performance of SiC DPFs onto which a nano-sized 2% CuO/ceria-zirconia catalyst was incorporated. Similarly to Rico Pérez and Bueno-López [16], these authors highlighted the importance to avoid catalyst/soot ratios lower than a critical ratio as they led to lower catalytic activities.…”

NOx Reduction Pathways during LNT Operation over Ceria Containing Catalysts: Effect of Copper Presence and Barium Content

“…It is clear that only the use of combined after-treatment characteristics have been attributed to a synergistic effect between CuO x sites and ceria's surface, which is due to their interfacial interactions that promote redox behavior [39][40][41][42][43]. The higher capacity of NO and/or NO 2 oxidation has also been exploited by our group, studying copper/ceria-zirconia catalysts in soot combustion processes (under NO + O 2 and under O 2 atmospheres) [44][45][46][47]. Nevertheless, a comprehensive study of the possibilities towards the NO x reduction of these catalysts is still lacking.…”

Impact Factors Analysis of Diesel Particulate Filter Regeneration Performance Based on Model and Test

“…Aluminum titanate and cordierite, compared to silicon carbide, can give significant advantages in reducing the temperature loss through DPF [13][14][15]. People have also investigated optimized coating technology, and several formulations for the catalytic coating of silicon carbide DPFs have been successfully tested [16][17][18][19][20].…”