DRIFTS study of the role of alkaline earths in promoting the catalytic activity of HC and NOx conversion over Pd-only three-way catalysts. Issue 3 (4th December 2014)

• Record Type: Journal Article
• Authors: Yang, Linyan; Yang, Xue; Lin, Siyu; Zhou, Renxian
• Is Part Of: Catalysis science & technology. Volume 5:Issue 3(2015:Mar.)
• Page Start: 1495
• Page End: 1503
• Publication Date: 2014-12-04
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c4cy01385a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Modification with alkaline earths, especially Ba, promotes NO x storage efficiency and NO dissociation, as well as the deep oxidation of HC. Thus doped catalysts present improved catalytic activity. Abstract : To reveal the role of alkaline earths modification in promoting the catalytic activity of HC and NO x conversion, catalytic activity tests and DRIFT experiments under different reaction conditions were performed. The introduction of alkaline earths promotes the catalytic activities of both HC and NO x elimination under stoichiometric NO x –CO–HC–O2 conditions, especially for Pd/CZBa, whereas it inhibits CO oxidation. In addition, the operation window of NO x conversion is also obviously widened as a result of enhanced NO x storage ability. DRIFTS results demonstrate that modification with alkaline earths improves the formation rate of nitrites and nitrates due to enhanced electron transfer and oxygen mobility, as well as the dissociation of NO species on the active metal, which increases the storage ability and reduction performance of NO x . On the other hand, the doping of alkaline earths could weaken the inhibiting effect arising from strongly bonded HC species on NO adsorption and dissociation due to the promoted catalytic activity of HC deep oxidation, which promotes the reaction of CO and NO x at low temperature.