赵心怡¹， 任亦晨¹， 姜若兰¹， 刘剑勋¹， 张健^1，2， 刘伟¹， 王仲鹏¹

1.济南大学 水利与环境学院， 山东 济南 250022； 2.泉州南京大学环保产业研究院， 福建 泉州 362000

引用格式：

赵心怡， 任亦晨， 姜若兰， 等. 铈镨锰固溶体（CePrMnO_x）催化碳烟燃烧的性能及机制［J］. 中国粉体技术， 2025， 31（4）： 174-186.

ZHAO Xinyi， REN Yichen， JIANG Ruolan， et al. Performance and mechanism of cerium-praseodymium-manganese （CePrMnO_x） solid solution in catalytic soot combustion［J］. China Powder Science and Technology， 2025， 31（4）： 174-186.

DOI：10.13732/j.issn.1008-5548.2025.04.015

收稿日期： 2025-01-06， 修回日期： 2025-04-22，上线日期： 2025-06-03。

基金项目： 国家自然科学基金项目，编号： 21777055； 山东省自然科学基金项目，编号： ZR2024QE354， ZR2023MB100， ZR2021MB063；福建省自然科学基金项目，编号：2023J05090。

第一作者简介： 赵心怡（2001—），女，硕士生，研究方向为环境功能材料开发与应用。E-mail：3302289639@qq.com。

通信作者简介： 王仲鹏（1978—），男，教授，博士，博士生导师，科技部国家火炬计划专家，山东省优秀中青年科学家，山东省科技人才，研究方向为大气污染控制与催化技术。E-mail：chm_wangzp@ujn.edu.cn。

摘要： 【目的】 改善用于柴油颗粒过滤器中铈基催化剂的内在活性，提高其碳烟低温催化氧化性能。【方法】 采用十六烷基三甲基溴化铵（cetyltrimethylammonium bromide，CTAB）辅助共沉淀法制备CePrMnO_x三元固溶体催化剂，探究镨、锰元素掺杂对碳烟低温催化氧化活性的影响，并通过X射线粉末衍射仪、扫描电子显微镜、氮气吸附-脱附、X射线光电子能谱仪和氢气程序升温还原等对固溶体催化剂物理化学性质进行表征。【结果】 CePrMnO_x三元催化剂具有最优的低温氧化碳烟能力，其碳烟转化率为50%的温度比CeO₂降低67 ℃；镨、锰元素掺杂进入CeO₂晶格，形成更多氧缺陷，促进生成更多 Ce³⁺、Mn³⁺与表面活性氧。【结论】 镨锰共掺杂可有效改善CeO₂的氧化还原能力，促进表面活性氧的生成。

关键词： 铈基催化剂；碳烟氧化；掺杂；活性氧

Abstract

Objective To enhance the regeneration efficiency of diesel particulate filters (DPFs), it is necessary to increase the lattice oxygen mobility and active oxygen content, thus improving the soot oxidation capacity of the catalyst at medium and low temperatures. Therefore, it is critical to develop an efficient and cost-effective catalyst that can facilitate soot oxidation under these conditions.

Methods In this study, pure metal oxides, CePrO_x , and CePrMnO_x catalysts were synthesized using the cetyltrimethylammonium bromide (CTAB) assisted co-precipitation method. The physical and chemical properties of these catalysts were characterized by various analytical techniques. Their structure and morphology, defect degree, reduction ability, oxidation ability, and mech-anism were systematically studied.

Results and Discussion Based on the characterization and experimental results, the catalytic oxidation activity test curves of soot showed that co-doping with Pr and Mn increased lattice oxygen mobility and reactive oxygen content in the catalysts. Specifically, the CePrMnO_x catalyst exhibited superior low-temperature oxidation ability for soot, and its t₁₀ and t₅₀values were 85 ℃ and 67 ℃ lower than those of CeO₂, respectively. X-ray diffraction (XRD) results confirmed that Pr and Mn elements were successfully doped into CeO₂ lattice, leading to lattice distortion.This distortion, which altered the lattice symmetry and oxygen ion migration pathways, was likely the key factor in improving lattice oxygen mobility. Nitrogen adsorption-desorption experiments showed that the CePrMnO_x catalyst hada larger specific surface area and pore volume, suggesting more active sites for reactants to interact with, thus improving the catalytic efficiency. SEM results revealed the presence of nanorods in the CePrMnO_x catalyst, which improved the contact efficiency of active sites and further enhanced the catalytic performance. Raman and temperature-programmed reduction (TPR) results showed that the CePrMnO_x catalyst hada higher oxygen vacancy concentration and stronger reduction ability. X-ray photoelectron spectroscopy (XPS) results suggested that this was due to the higher content of Ce³⁺, Mn³⁺, and surface reactive oxygen species in the CePrMnO_x catalyst. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) results showed that carbonates were the main intermediate reaction products for both CePrO_x and CePrMnO_x catalysts.The bidentate carbonates on the surface of the CePrO_x catalyst did not fully participate in the reaction， thus covering the active sites and limiting the improvement of catalytic activity. In contrast, the CePrMnO_x catalyst, with its higher active oxygen content and oxygen vacancy concentration, promoted carbonate conversion more effectively, thus improving the catalytic efficiency.

Conclusion 1) The CTAB-assisted co-precipitation method not only maintains the cubic fluorite structure of CeO₂ but also successfully introduces Pr and Mn elements into the CeO₂ lattice. This co-doped catalyst exhibits a larger specific surface area and has more active sites for reactant interaction, thus improving catalytic activity. Moreover, this method enhances the redox capacity of the catalyst, which is particularly important for catalytic oxidation reactions.It promotes the activation and transfer of oxygen, thereby improving the catalytic efficiency. 2) Mn doping has a significant impact on catalyst performance. The introduction of Mn enhances the oxygen migration ability of the catalyst and increases the content of chemisorbed oxygen on the surface. Efficient oxygen migration is vital for soot oxidation. Additionally, higher surface chemisorbed oxygen content means more oxygen molecules can be adsorbed on the catalyst surface, providing more reactive oxygen species for oxidation reactions. These characteristics collectively improve the catalyst performance in soot oxidation reactions, making it more efficient at low temperatures. 3) During soot oxidation, bidentate carbonates are the main reactive species. However, bidentate carbonates on the surface of the CePrO_x catalyst may cover active sites, reducing catalytic activity. This occurs because the adsorption of bidentate carbonates may hinder reactant contact with the active site. In contrast, the CePrMnO_x catalyst, due to its optimized surface properties and enhanced oxygen migration capacity, can convert bidentate carbonates more efficiently. This reduces active site coverage and improves catalyticactivity. These findings indicate that the CePrMnO_x catalyst performs better in soot oxidation, which is significant for improving catalytic efficiency and reducing environmental pollution.

Keywords： cerium-based catalyst; soot oxidation; doping; active oxygen

参考文献（References）

［1］汪涛，陈明功，赵彬彬，等. 柴油车尾气颗粒物净化研究进展［J］. 山东化工，2024，53（3）：71-73， 76.

WANG T, CHEN M G, ZHAO B B, et al. Research progress of particulate matter purification from diesel vehicle exhaust［J］. Shandong Chemical Industry, 2024, 53（3）：71-73， 76.

［2］李游，王忠，刘帅，等. 柴油机排气颗粒结构及力学表征［J］. 中国粉体技术，2020，26（2）：70-74.

LI Y, WANG Z, LIU S, et al. Structure and mechanical characterization of diesel exhaust particles ［J］. China Powder Science and Technology, 2020, 26（2）： 70-74.

［3］WANG Y H, XIE Y, ZHANG C, et al. Tuning the oxygen mobility of CeO₂ via Bi-doping for diesel soot oxidation: experimental and DFT studies［J］. Journal of Environmental Chemical Engineering, 2021, 9（1）： 105049.

［4］朱敬芳，杜奥林，高琨阳，等. 催化碳烟氧化用PtCe_xZr_1-xO₂催化剂的制备及性能研究［J］. 贵金属，2021，42（2）：49-55， 61.

ZHU J F, DU O L, GAO K Y, et al. Preparation and properties of PtCe_xZr_1-xO₂ catalyst for soot oxidation［J］. Precious Metals, 2021, 42（2）： 49-55， 61.

［5］HADI A, YAACOB I I. Novel synthesis of nanocrystalline CeO₂ by mechanochemical and water-in-oil microemulsion methods［J］. Materials Letters, 2007, 61（1）： 93-96.

［6］BUENO-LÓPEZ A. Diesel soot combustion ceria catalysts［J］. Applied Catalysis B: Environmental, 2014, 146： 1-11.

［7］GUILLÉN-HURTADO N, GARCÍA-GARCÍA A, BUENO-LÓPEZ A. Active oxygen by Ce-Pr mixed oxide nanoparticles outperform diesel soot combustion Pt catalysts［J］. Applied Catalysis B: Environmental, 2015, 174： 60-66.

［8］JEONG E J, LEE J H, LEE S H, et al. Ce‐Pr mixed oxide catalysts with a fibrous morphology for low-temperature PM oxidation［J］. ChemCatChem, 2019, 11（8）： 2131-2141.

［9］GUILLÉN-HURTADO N, GIMÉNEZ-MAÑOGIL J, MARTÍNEZ-MUNUERA J C, et al. Study of Ce/Pr ratio in ceria-prase-odymia catalysts for soot combustion under different atmospheres［J］. Applied Catalysis A: General, 2020, 590： 117339.

［10］SELLERS-ANTÓN B, BAILÓN-GARCÍA E, DAVÓ-QUIÑONERO A, et al. Shaping a soot combustion Ce_0.5Pr_0.5O_x catalyst［J］. Applied Surface Science, 2022, 584： 152513.

［11］GRABCHENKO M V, MIKHEEVA N N, MAMONTOV G V, et al. Unraveling the structural and compositional peculiarities in CTAB-templated CeO₂-ZrO₂-MnO_x catalysts for soot and CO oxidation［J］. Nanomaterials, 2023, 13（24）： 3108.

［12］GRABCHENKO M V, MAMONTOV G V, CHERNYKH M V, et al. Synergistic effect in ternary CeO₂-ZrO₂-MnO_x catalysts for CO oxidation and soot combustion［J］. Chemical Engineering Science, 2024, 285： 119593.

［13］DOROFEEVA N V, SAVEL’EVA A S, GRABCHENKO M V, et al. Ce-Zr-Mn oxide catalysts for soot combustion： the role of preparation method［J］. The Journal of Physical Chemistry C, 2024, 128（32）： 13432-13444.

［14］白鸽. CO氧化反应催化剂的研究进展［J］. 材料化学前沿， 2022， 10（2）： 36-42.

BAI G. Research progress of catalysts in CO oxidation［J］. Advances in Material Chemistry, 2022, 10（2）： 36-42.

［15］YU Y, LIU S L, JI J, et al. Amorphous MnO₂ surviving calcination: an efficient catalyst for ozone decomposition［J］. Catalysis Science & Technology, 2019, 9（18）： 5090-5099.

［16］朱艺，邓冯丹，李晓倩，等. 陈化时间对铈锰碳烟颗粒物催化剂性能的影响［J］. 现代化工，2023，43（9）：150-154.

ZHU Y, DENG F D, LI X Q, et al. Effect of aging time on properties of cerium manganese carbon smoke particulate matter catalysts［J］. Modern Chemical Industry, 2023, 43（9）： 150-154.

［17］ZHU Y, CHEN Z, LI H M, et al. Effect of oxygen vacancy and highly dispersed MnO_x on soot combustion in cerium manganese catalyst［J］. Scientific Reports, 2023, 13（1）： 3386.

［18］ZHU Y, WANG Q, LAN L, et al. Effect of surface manganese oxide species on soot catalytic combustion of Ce-Mn-O catalyst［J］. Journal of Rare Earths, 2022, 40（8）： 1238-1246.

［19］SHOURYA A, DASARI H. Manganese doped Ceria (Ce_1-xMn_xO_2-δ（x=0-0.3）) catalysts synthesized by EDTA-citrate method for soot oxidation activity［J］. Chemical Papers, 2022, 76（11）： 7095-7110.

［20］YU D, PENG C, REN Y, et al. Low temperature oxidation of diesel soot particles over one-dimensional 2 x 3 tunnel-structured Na₂Mn₅O₁₀ catalysts［J］. Applied Catalysis B: Environmental, 2024, 344.

［21］朱艺，师伟，刘星语，等. 聚乙二醇辅助Ce_0.6Mn_0.4O_x催化净化碳烟颗粒物燃烧性能的研究［J］. 环境科学学报，2024，44（2）：355-364.

ZHU Y, SHI W, LIU X Y, et al. Study on combustion performance of PEG-assisted Ce_0.6Mn_0.4O_x catalytic purification of soot particles ［J］. Journal of Environmental Sciences, 2024, 44（2）： 355-364.

［22］陈世鸿，唐诗昌，庄檾希，等. 制备方法对铈锰固溶体催化燃烧甲苯性能的影响［J］. 中国粉体技术，2023，29（4）：138-149.

CHEN S H, TANG S C, ZHUANG Q X, et al. Effect of preparation method on catalytic combustion performance of toluene in cerium-manganese solid solution ［J］. China Powder Science and Technology, 2023, 29（4）： 138-149.

［23］CHEN Z, CHEN L L, JIANG M, et al. Controlled synthesis of CeO₂ nanorods and their promotional effect on catalytic activity and aging resistibility for diesel soot oxidation［J］. Applied Surface Science, 2020, 510： 145401.

［24］LORIDANT S. Raman spectroscopy as a powerful tool to characterize ceria-based catalysts［J］. Catalysis Today, 2021, 373： 98-111.

［25］OLIVEIRA L L, CORTÉS J A, CALDEIRA B S, et al. Structural, electronic paramagnetic resonance and magnetic properties of praseodymium-doped rare earth CeO₂ semiconductors［J］. Ceramics International, 2021, 47（15）： 20768-20780.

［26］LI X L, CHEN R J, YANG M, et al. Insight into modified Ce Mn based catalysts for efficient degradation of toluene by in situ infrared［J］. Science of the Total Environment, 2024, 912： 169192.

［27］WANG P, ZHANG S J, XU Z K, et al. Fabrication of porous and highly defective CeO₂-based catalysts for soot combustion with the strategy of soft-template addition and matrix doping by multiple rare earth elements［J］. Catalysis Today, 2024, 437： 114765.

［28］OHNO Y. XPS studies of the intermediate valence state of Yb in （YbS）_1.25CrS₂［J］. Journal of Electron Spectroscopy and Related Phenomena, 2008, 165（1）： 1-4.

［29］XIAO Z R, LI Y T, HOU F, et al. Engineering oxygen vacancies and nickel dispersion on CeO₂ by Pr doping for highly stable ethanol steam reforming［J］. Applied Catalysis B: Environmental, 2019, 258： 117940.

［30］DENG Y B, FU L, SONG W J, et al. Transition metal and Pr co-doping induced oxygen vacancy in Pd/CeO₂ catalyst boosts low-temperature CO oxidation［J］. Separation and Purification Technology, 2023, 311： 123247.

［31］JIN B F, LIU Y, MA Y, et al. Modification of SmMn₂O₅ catalyst with silver for soot oxidation: Ag loading and metal-support interactions［J］. Catalysts, 2024, 14（2）： 135.

［32］王犇，潘齐，刘剑勋，等. 溶液燃烧制备镧基钙钛矿及其催化碳烟燃烧性能［J］. 中国粉体技术，2023，29（3）：92-100.

WANG B, PAN Q, LIU J X, et al. Preparation of lanthanide perovskite by solution combustion and its catalytic performance for soot combustion ［J］. China Powder Science and Technology, 2023, 29（3）： 92-100.

［33］CHEN L W, LI T, ZHANG J, et al. Chemisorbed superoxide species enhanced the high catalytic performance of Ag/Co₃O₄ nanocubes for soot oxidation［J］. ACS Applied Materials & Interfaces, 2021, 13（18）： 21436-21449.

［34］刘爽，方子昂，吴晓东. CeO₂基材料用于汽油车碳烟燃烧：反应机理与催化剂设计［J］. 中国稀土学报，2022，40（3）：351-365.

LIU S, FANG Z A, WU X D. Application of CeO₂-based materials to soot combustion in gasoline vehicles： reaction mechanism and catalyst design ［J］. Chinese Journal of Rare Earths, 2022, 40（3）： 351-365.

［35］朱洪健. CTAB辅助合成铈基固溶体催化氧化碳烟和CO［D］. 济南：济南大学，2018.

ZHU H J. CTAB assisted synthesis of cerium based solid solution catalyzed oxidation of soot and CO［D］. Jinan: University of Jinan, 2018.

［36］LI H F, PAN Q, LIU J X, et al. Synthesis and catalytic properties of praseodymium oxide (Pr₆O₁₁) nanorods for diesel soot oxidation［J］. Journal of Environmental Chemical Engineering, 2023, 11（1）： 109152.

［37］ZHANG X M, DENG Y Q, TIAN P, et al. Dynamic active sites over binary oxide catalysts: in situ/operando spectroscopic study of low-temperature CO oxidation over MnO_x-CeO₂ catalysts［J］. Applied Catalysis B： Environmental, 2016, 191： 179-191.

［38］VENKATASWAMY P, JAMPAIAH D, RAO K N, et al. Nanostructured Ce_0.7Mn_0.3O_2-δ and Ce_0.7Fe_0.3O_2-δ solid solutions for diesel soot oxidation［J］. Applied Catalysis A: General, 2014, 488： 1-10.

［39］NITHYA R, VIKRAM A L, DASARI H, et al. Improved catalytic performance of Ag-doped K-OMS-2 for soot oxidation［J］. Applied Physics A: Materials Science & Processing, 2024, 130（2）： 112.

［40］XU J C, WU Z, GAO E, et al. Revealing the role of oxygen vacancies on α-MnO₂ of different morphologies in CO oxidation using operando DRIFTS-MS［J］. Applied Surface Science, 2023, 618： 156643.

［41］WANG Y X, LI D Y, LI K Z, et al. Enhanced propane and carbon monoxide oxidation activity by structural interactions of CeO₂ with MnO_x/Nb₂O_5-x catalysts［J］. Applied Catalysis B: Environmental, 2020, 267： 118363.