Abstract This study concentrates on improving the low temperature performance of CDPF catalysts. The self-propagating high temperature combustion synthesis method was applied to synthesize a series of CeZrO2-δ, CuCeZrO2-δ, and MnCuCeZrO2-δ catalysts, which were coated on DPF substrate. The performance of the catalysts was fully investigated by the soot temperature programmed combustion, which showed that these catalysts with nanometer size have a high catalytic activity of soot combustion at low temperatures. Compared with Ce0.05Zr0.05O2-δ, Cu0.9Ce0.05Zr0.05O2-δ and Mn0.09Cu0.81Ce0.05Zr0.05O2-δ showed excellent low temperature soot oxidation activities and much higher CO2 selectivity. BET, XRD, TEM, and XPS were employed to characterize the structural and physical-chemical properties of catalysts. The XRD results indicated that catalysts with 90% Cu possess evenly distributed crystalline grains and small particle size, which is responsible for its excellent oxidation activity by providing more active sites as well as forming good connection between the catalyst and soot. The XPS results demonstrated that the Cux+ has a significant association with the formation of NO2, thus promoting the soot oxidation, and that the synergetic effect between Cux+ and Mnx+ contributes most to the improvement of the catalytic activity. The partial substitution with Mn could enhance the chemisorbed oxygen, which further improved NO oxidation and CO2 selectivity. Furthermore, the soot combustion reaction mechanism was examined with in situ DRIFTS. The results exhibited that the active sites of Cu0.9Ce0.05Zr0.05O2-δ and Mn0.09Cu0.81Ce0.05Zr0.05O2-δ could generate more reactive oxygen for NO oxidation and that the uniformly dispersed Cux+ and Mnx+ in Ce lattice could adsorb NO2 to form nitrite and nitrates, which behaved as a carrier of NO2 and transported it around the surface of soot, thus facilitating the soot combustion, especially at low temperatures.

中文翻译：

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自蔓延高温合成法制备的Cu、Mn取代CeZrO 2-δ 纳米复合催化剂对碳烟的催化燃烧

摘要 本研究集中于提高CDPF催化剂的低温性能。采用自蔓延高温燃烧合成法合成了一系列CeZrO2-δ、CuCeZrO2-δ和MnCuCeZrO2-δ催化剂，并包覆在DPF基材上。通过烟尘程序升温燃烧充分考察了催化剂的性能，结果表明这些纳米尺寸的催化剂在低温下具有较高的烟尘燃烧催化活性。与 Ce0.05Zr0.05O2-δ 相比，Cu0.9Ce0.05Zr0.05O2-δ 和 Mn0.09Cu0.81Ce0.05Zr0.05O2-δ 表现出优异的低温烟尘氧化活性和更高的 CO2 选择性。BET、XRD、TEM 和 XPS 被用来表征催化剂的结构和物理化学性质。XRD 结果表明，含 90% Cu 的催化剂具有均匀分布的晶粒和小粒径，这通过提供更多的活性位点以及在催化剂和烟尘之间形成良好的连接而具有优异的氧化活性。XPS 结果表明，Cux+ 与 NO2 的形成有显着关联，从而促进烟尘氧化，并且 Cux+ 和 Mnx+ 之间的协同作用对催化活性的提高贡献最大。Mn 的部分取代可以增强化学吸附的氧，从而进一步提高 NO 氧化和 CO2 选择性。此外，用原位 DRIFTS 检查了烟尘燃烧反应机理。结果表明，活性位点为Cu0.9Ce0.05Zr0.05O2-δ和Mn0.09Cu0.81Ce0.05Zr0。