Ultrasound-Assisted Deposition of Co–CeO₂ onto Ceramic Microfibers to Conform Catalytic Papers: Their Application in Engine Exhaust Treatment

Abstract

The combination of the selective catalytic reduction technology with catalytic filters constitutes one of the most efficient ways for diesel engine exhaust treatment. In this paper, the development of catalytic ceramic papers as structured systems for the abatement of diesel soot particles is addressed. Ceramic papers were prepared by the dual-polyelectrolyte papermaking method, which is based on the conventional papermaking technique used for cellulosic papers, in which a portion of cellulosic fibers is replaced by ceramic ones. The deposition of Co and Ce as catalytic materials by the wet spray method on ceramic papers was studied for the development of structured catalysts using an ultrasonic nebulizer and different solvents. The use of alcohol–water solutions for the impregnation of cobalt generated smaller particles and a high dispersion of them on the ceramic fibers, greater than that obtained when pure water was employed. Temperature programmed oxidation (TPO) assays showed that the best catalytic performance was acquired with the catalysts generated with alcohol solvents, showing a maximum rate for soot combustion at a temperature close to 400 °C. The adequate soot combustion performance and the high thermal and catalytic stability make catalytic ceramic papers impregnated by the wet spray method, promising systems for their application as diesel particulate filters.

Most Recent Advances in Diesel Engine Catalytic Soot Abatement: Structured Catalysts and Alternative Approaches

“…Sacco et al investigated the performance of catalytic ceramic papers prepared by using the dual-polyelectrolyte papermaking method that consisted of modifying the conventional papermaking technique used for cellulosic papers, by substituting the cellulosic fibers with ceramic ones [52]. The authors used Co and Ce as active species, which were deposited by the wet spray method using an ultrasonic nebulizer; the authors also investigated the effect of using different solvents in the preparation procedure on the final catalyst.…”

Electrospinning synthesis and characterization of nanofibers of Co, Ce and mixed Co-Ce oxides. Their application to oxidation reactions of diesel soot and CO

“…Many of the new structures are based on fibers made from different materials, which have several beneficial aspects in reaction engineering applications. Among them, fibrous substrates can be fitted to various geometries due to their flexibility and can be made of different materials as ceramic, metal and glass [1,2].…”

“…Catalytic materials based on Co and Ce oxides mixtures have been proven to be efficient for deep oxidation reactions [2,3,16]. Taking this fact into account, and the advantages of fiber structures, the present work aimed to develop efficient catalytic nanofibers made of Co oxide, Ce oxide and the mixed Co-Ce fibers using the electrospinning technique for their application in the catalytic oxidation of environmental pollutants.…”