High performance of an ultra-low Pt loading diesel oxidation catalyst can be achieved by using a combination of novel nano-array structured support, precise control of ultrafine active Pt particles, and an addition of H₂ as a promoter into the exhausts. Highly stable mesoporous rutile TiO₂ nano-array was uniformly grown on three-dimensional (3-D) cordierite honeycomb monoliths using a solvothermal synthesis. Atomic layer deposition was employed for precise dispersion of ultrafine Pt particles (0.95 ± 0.24 nm) on TiO₂ nano-array with a Pt loading of 1.1 g/ft³. Despite low Pt loading, the Pt/TiO₂ nano-array catalyst shows impressive low-temperature oxidation reactivity, with the conversion of CO and total hydrocarbon (THC) reaching 50% at 224 and 285 °C, respectively, in the clean diesel combustion (CDC) simulated exhaust conditions. The excellent activity is attributed to the unique nano-array structure that promotes gas-solid interaction and ultra-small Pt particle dispersion that increase surface Pt atoms. We also demonstrate that addition of more H₂ into the exhaust can lower light-off temperature for CO and THC by up to ∼60 °C and ∼30 °C, respectively.

通过结合使用新型纳米阵列结构载体，精确控制超细活性Pt颗粒以及在废气中添加H ₂作为促进剂，可以实现超低Pt负载柴油氧化催化剂的高性能。使用溶剂热合成法将高稳定性的介孔金红石型TiO ₂纳米阵列均匀地生长在三维（3-D）堇青石蜂窝状整料上。原子层沉积用于将超细Pt颗粒（0.95±0.24 nm）精确分散在TiO ₂纳米阵列上，Pt负载为1.1 g / ft ³。尽管Pt含量低，但Pt / TiO ₂纳米阵列催化剂显示出令人印象深刻的低温氧化反应性，在清洁柴油燃烧（CDC）模拟的排气条件下，CO和总烃（THC）的转化率分别在224和285°C时达到50％。出色的活性归因于独特的纳米阵列结构，该结构促进了气固相互作用和超小Pt颗粒分散，从而增加了表面Pt原子。我们还证明，向排气中添加更多的H ₂可以分别将CO和THC的起燃温度分别降低约60°C和30°C。