Catalytic combustion is widely regarded as the most efficient technique for removing soot particulates from diesel engine exhaust, with its efficiency largely dependent on the performance of catalysts. In this study, a series of YMn_1-xCo_xO_5-ζ catalysts were synthesized using a hydrothermal method to investigate their catalytic properties in soot oxidation. Among these catalysts, YMCo-0.2 exhibited the highest catalytic activity, achieving 90% soot conversion at 392 °C and demonstrating robust tolerance in the presence of water vapour and SO₂. Structural characterisation revealed that Co doping did not alter the fundamental crystal structure of YMn₂O₅ mullite. Through some characterization comprehensive analysis, and DFT calculations further supported the experimental findings, indicate that Co substitution significantly increased the lattice oxygen mobility and surface active oxygen content. Compared to the surface lattice oxygens at other positions, the weakening of the Mn-O bond results in the lattice oxygens in the Co-O-Mn⁴⁺ sites in the catalysts exhibiting higher reactivity. Additionally, the catalyst displayed strong NO and O₂ adsorption and activation capabilities, indicating its potential for efficient NO_x-assisted soot combustion. This study provides insights for designing and optimizing mullite catalysts for soot combustion.

Environmental implications

The catalytic removal of soot particles from diesel exhaust is crucial for protecting both environmental quality and human health. In this work, cobalt (Co) doping into YMn₂O₅ mullite decreased the strength of Mn-O bond and increased the adsorption capacity of NO, which was beneficial to soot combustion reaction. This research enriches the application of mullite in the field of environmental catalysis.

中文翻译：

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通过钴掺杂增强 NOx 辅助烟尘燃烧，以削弱莫来石 Mn-O 键以实现晶格氧活化


催化燃烧被广泛认为是去除柴油发动机废气中烟尘颗粒的最有效技术，其效率在很大程度上取决于催化剂的性能。在本研究中，使用水热法合成了一系列 YMn_1-xCo_xO_5-ζ 催化剂，以研究它们在烟尘氧化中的催化性能。在这些催化剂中，YMCo-0.2 表现出最高的催化活性，在 392 °C 时实现了 90% 的烟尘转化率，并在水蒸气和 SO₂ 存在下表现出强大的耐受性。结构表征表明，Co 掺杂不会改变 YMn₂O₅ 莫来石的基本晶体结构。通过一些表征综合分析，以及 DFT 计算进一步支持实验结果，表明 Co 取代显著提高了晶格氧迁移率和表面活性氧含量。与其他位置的表面晶格氧相比，Mn-O 键的减弱导致催化剂中 Co-O-Mn⁴⁺ 位点的晶格氧表现出更高的反应性。此外，该催化剂表现出很强的 NO 和 O₂ 吸附和活化能力，表明其具有高效 NO_x 辅助烟尘燃烧的潜力。本研究为设计和优化用于烟尘燃烧的莫来石催化剂提供了见解。

环境影响

催化去除柴油机尾气中的烟尘颗粒对于保护环境质量和人类健康至关重要。在本工作中，钴 （Co） 掺杂到 YMn₂O₅ 莫来石中降低了 Mn-O 键的强度，增加了 NO 的吸附能力，有利于烟尘燃烧反应。本研究丰富了莫来石在环境催化领域的应用。