Highly reactive and thermally stable Ag/YSZ catalysts with macroporous fiber-like morphology for soot combustion

Abstract

The contact between catalysts and soot has been widely held as a crucial factor affecting the catalytic soot combustion, while efforts to improve the catalyst-soot contact efficiency remain both highly desirable and challenging. Herein, a hierarchical Ag/YSZ catalyst with macroporous fiber-like morphology was synthesized via a template electrospinning method. Based on the quantitative approach developed in this work, the soot accessibility of this catalyst with engineered morphology was 6.75 times higher than that of a conventional bulk Ag/YSZ catalyst. After the ageing treatments at 800 °C, the silver species on the fibrous Ag/YSZ redispersed into fine Ag nanoparticles, which provided abundant electrophilic O− species and led to a T50 of 372 °C for soot combustion in a “loose” contact mode. This strategy of fabricating macroporous fiber-like materials provides a new opportunity to improve the soot elimination efficiency of catalyzed gasoline particulate filters.