Structured catalysts based on sepiolite with tailored porosity to remove diesel soot

FERNANDO TULER; RAQUEL PORTELA; PEDRO AVILA; EZEQUIEL BANÚS; EDUARDO E. MIRÓ; VIVIANA G. MILT

APPLIED CATALYSIS A-GENERAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 498 p. 41 - 53

0926-860X

Wall-flow monolithic filters are commonly made of silicon carbide or cordierite and present high poros-ity, but low surface area. Alternatively, wall-flow monoliths with high surface area can be employed assupport for active phases that catalyze the elimination of the particles deposited in the pores. In thisstudy, mesoporous monoliths with tailored macroporosity are obtained by extrusion using sepiolite clayand different pore generating agents. Cobalt, barium and potassium were incorporated as active phasesduring the kneading of the dough or by impregnation of the structured material to give the monolithsthe capacity for catalytically burning soot under the conditions of diesel engine exhausts. The incorpo-rated and impregnated catalytic monoliths were morphologically, mechanically and physical-chemicallycharacterized at different preparation stages to study the influence of support porosity and the methodof addition of active phases in the catalytic activity for diesel soot combustion. The most active catalystwas obtained impregnating the active components to a previously extruded monolith calcined at 850◦C,and then calcining the assembly at 600◦C, for which the temperature of maximum soot combustion ratewas 385◦C.