Nithya R, Patil Sunaina S, Dasari Hari Prasad, Dasari Harshini, Nethaji S
Department of Chemical Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, 576104, Manipal, Karnataka, India.
Energy & Catalysis Materials Laboratory, Department of Chemical Engineering, National Institute of Technology Karnataka, 575025, Surathkal, Mangalore, India.
Sci Rep. 2025 Jan 7;15(1):1174. doi: 10.1038/s41598-025-85736-2.
Efficient catalysts for soot oxidation are critical for mitigating environmental pollution. In this study, CoMnO spinel catalysts were synthesised using reverse co-precipitation and co-precipitation methods to evaluate their performance in soot oxidation and kinetic behaviour. All samples exhibited a tetragonal phase (XRD) and spherical morphology with rough surfaces (SEM). Raman spectroscopy confirmed structural disorder and oxygen vacancies, while XPS analysis revealed the presence of low-valence Mn ions, facilitating oxygen vacancy formation critical for soot oxidation. Additionally, the co-existence of Co and Mn ions contributed to a synergistic effect, enhancing the catalytic properties of the spinel structure. The reverse co-precipitation method produced a catalyst with a higher concentration of oxygen vacancies and active oxygen species among the samples. This sample demonstrated superior catalytic performance, achieving a T of 424 °C, low activation energy (153 kJ/mol) and pre-exponential factor (25 min). Soot TPR analysis highlighted the role of catalyst reducibility, while thermogravimetric analysis revealed that activation energy and pre-exponential factors were influenced by surface composition. These findings provide valuable insights into the design of efficient catalysts for soot oxidation, emphasising the importance of synthesis methods and surface characteristics.
高效的碳烟氧化催化剂对于减轻环境污染至关重要。在本研究中，采用反向共沉淀法和共沉淀法合成了CoMnO尖晶石催化剂，以评估其在碳烟氧化中的性能和动力学行为。所有样品均呈现四方相（XRD）和表面粗糙的球形形态（SEM）。拉曼光谱证实了结构无序和氧空位，而XPS分析表明存在低价Mn离子，这有利于形成对碳烟氧化至关重要的氧空位。此外，Co和Mn离子的共存产生了协同效应，增强了尖晶石结构的催化性能。在样品中，反向共沉淀法制备的催化剂具有更高浓度的氧空位和活性氧物种。该样品表现出优异的催化性能，T 为424℃，活化能低（153 kJ/mol），指前因子低（25 min）。碳烟TPR分析突出了催化剂还原能力的作用，而热重分析表明活化能和指前因子受表面组成的影响。这些发现为设计高效的碳烟氧化催化剂提供了有价值的见解，强调了合成方法和表面特性的重要性。
