Acanthosphere-like CeO2 with porous spikes for efficient diesel soot catalytic combustion

Abstract

Catalytic combustion is regarded as an efficient strategy to eliminate the soot particulates emitted from diesel engines. Whereas the insufficient contact between the catalyst and soot particulates, as well as the inferior redox capacity of catalysts, restrict the deployment of this technique. In this study, a uniform acanthosphere-like CeO2 catalyst (asl-CeO2) endowed with porous spikes was rationally designed and prepared. It displayed outstanding catalytic performance for the soot combustion compared to commercial CeO2 sample (com-CeO2) under different contact modes and with NO addition. The structure–activity relationship was unveiled based on various characterizations. The acanthosphere-like morphology and porous spikes not only enhanced the contact efficiency between the soot particulates and catalytic sites but also benefited the mass transfer of gaseous molecules during the reaction. The XPS, Raman, H2-TPR and Soot-TPR results have revealed that the abundant oxygen vacancies and strong redox capacity were involved in the asl-CeO2. Meanwhile, asl-CeO2 was also demonstrated high thermal stability and water resistance.