An Efficient Cu/BaO/La2O3 Catalyst for the Simultaneous Removal of Carbon Soot and Nitrogen Oxides from Simulated Diesel Exhaust

详细信息    查看全文

• 作者：Kohsuke Mori ; Yoshiro Iwata ; Makoto Yamamoto ; Naoto Kimura ; Akihiko Miyauchi ; Go Okamoto ; Takahiro Toyoshima ; Hiromi Yamashita
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：May 1, 2014
• 年：2014
• 卷：118
• 期：17
• 页码：9078-9085
• 全文大小：380K
• 年卷期：v.118,no.17(May 1, 2014)
• ISSN：1932-7455

文摘

A three-component Cu/BaO/La₂O₃ catalyst has been developed as a highly efficient catalyst for the simultaneous removal of carbon soot and NO gas from diesel emissions. The influence of transition metals (Cu, Pd, Ni, Co, and Pt) deposited on BaO/La₂O₃ supports and cosupports (BaO, SrO, CaO, and CeO₂) combined with La₂O₃ were investigated. The Cu/BaO/La₂O₃ catalyst completely combusted 50 wt % carbon soot under an O₂ atmosphere, with a T50% temperature of 375 掳C. This catalyst also exhibited the highest activity among the investigated catalyst systems for the simultaneous removal of carbon soot and NO gas, even at low temperatures. The absence of carbon soot substantially decreased the NO conversion rate that suggested carbon soot acts as a solid reductant for the NO reduction. The high activity of the Cu/BaO/La₂O₃ system can be attributed to the high oxygen storage capacity (OSC) of the BaO phase on La₂O₃ and to the redox properties of the Cu species that are attributable to strong Cu鈥揃aO interactions. The Cu/BaO/La₂O₃ also exhibits high durability and good recyclability without any appreciable loss of catalytic activity. We propose that the present catalytic reaction consists of two reaction pathways: (i) direct soot oxidation by surface oxygen species and (ii) NO_x-assisted soot oxidation. The use of significantly cheaper Cu rather than noble metals makes the Cu/BaO/La₂O₃ catalyst a strong candidate to satisfy today鈥檚 industrial requirements because of its lack of a precious metal.