Cobalt aluminate spinel compounds prepared by different methods were characterized in terms of crystalline structure, morphology, textural properties and acidity, and evaluated as catalysts for diesel soot combustion in NO_x/O₂ mixtures. The activation of commercial CoAl₂O₄ microparticles by ball milling reduced the onset temperature of this material considerably and yielded an efficient catalyst for soot combustion that exhibited a temperature of half conversion, 411 °C, similar to that obtained with the reference Pt/Al₂O₃ catalyst. Moreover, like Pt, the milled CoAl₂O₄ suppressed the CO formation observed in non-catalytic soot combustion. The significant modification of the particle size, the emergence of new exposed crystal facets and the creation of defects are responsible for the appearance of new active sites and high acidity that improved catalyst-to-soot contact and reactivity. The findings open a new gate toward the use of efficient Pt-free catalyst for soot combustion.

通过不同方法制备的铝酸钴尖晶石化合物的晶体结构，形态，质构性质和酸度均经过表征，并作为NO _x / O ₂混合物中柴油烟diesel燃烧的催化剂进行了评估。通过球磨对商业CoAl ₂ O ₄微粒的活化大大降低了该材料的起始温度，并产生了一种有效的烟灰燃烧催化剂，其催化转化温度为411°C，与使用参比Pt / Al所获得的转化率相似₂ O ₃催化剂。而且，像Pt一样，研磨后的CoAl ₂ O ₄抑制了在非催化性烟灰燃烧中观察到的一氧化碳的形成。粒径的显着改变，新暴露的晶体面的出现以及缺陷的产生是新的活性位点和高酸度的出现的原因，新的活性位点和高酸度改善了催化剂与烟灰的接触和反应性。这些发现为使用有效的无铂催化剂进行烟尘燃烧打开了新的大门。