张葆逸， 高兴敏， 严珅， 王晓宁， 吴铎
苏州大学 材料与化学化工学部， 先进粉体技术工程研究中心， 江苏 苏州 215123
引用格式：
张葆逸， 高兴敏， 严珅， 等. 氧化铈基铜催化剂的制备及其对草酸钠的降解性能［J］. 中国粉体技术， 2025， 31（5）： 1-12.
ZHANG Baoyi， GAO Xingmin， YAN Shen， et al. Preparation of ceria-based copper catalysts and their degradation performance for sodium oxalate［J］. China Powder Science and Technology， 2025， 31（5）： 1-12.
DOI：10.13732/j.issn.1008-5548.2025.05.009
收稿日期： 2025-03-12， 修回日期： 2025-06-05，上线日期： 2025-06-26。
基金项目： 国家自然科学基金项目，编号：21906111；江苏省教育厅自然科学研究重大项目，编号：18KJA530004。
第一作者简介： 张葆逸（1999—），男，硕士生，研究方向为催化剂制备。E-mail：20225209020@stu.suda.edu.cn。
通信作者简介： 吴铎（1981—），男，教授，博士，博士生导师，江苏省“双创博士”引进人才，研究方向为吸入药物粉体制剂研发、 干细胞体外三维培养微载体创制、 废水深度处理催化剂材料及装备研发、 新型喷雾制粒装备设计与工艺优化等。E-mail：duo.wu@suda.edu.cn。
摘要： 【目的】 草酸钠是一种具有代表性的难降解有机污染物，为了提高对水中草酸钠的降解率，制备具有多级孔结构的氧化铈基铜催化剂，研究氧化铈基铜催化剂的臭氧（O3）催化氧化机制，提高O3在溶液中的传质效率，加速O3的分解与转化。【方法】 以NaCl为盐模板，以酚醛树脂（PF）为定型剂，通过喷雾干燥法和辅助盐模板法制备氧化铈基铜催化剂，在同样的工艺条件下改变NaCl、PF的添加量制得不同氧化铈基铜催化剂样品；采用XRD谱图、SEM图像、孔径分布曲线和XPS图谱对各种样品进行表征；研究各种氧化铈基铜催化剂样品对水中草酸钠的降解率，确定具有最佳降解性能的样品；进行4次重复降解实验研究最佳样品的循环使用的稳定性，并探讨氧化铈基铜催化剂的O3催化氧化机制。【结果】 随着NaCl加入量的增大，各种催化剂样品的粒径明显增大，而PF的加入量对粒径影响较小，对样品的孔结构和比表面积影响较大；当NaCl与PF的质量比为1：1时，制得的样品Cu@CeO2-NaCl-PF的粒径约为35.3 nm，介孔孔径为5~45 nm，大孔孔径约为3 000~25 000 nm，比表面积为 52.15 m2/g，介孔体积、大孔体积、总孔体积分别为0.240、4.778、5.115 mL/g，所含的Cu0-Cu+、Ce3+的质量分数分别为67.1%、18.7%；在降解时间为45 min时，样品Cu@CeO2-NaCl-PF对水中草酸根的降解率达到100%；在降解时间为60 min时，第4次循环使用的样品Cu@CeO2-NaCl-PF对草酸根的降解率为95%，溶液中残留的Cu元素的质量浓度依次为0.23、0.27、0.34、0.37 mg/L；在加入浓度为1 mmol/L的叔丁醇作为溶液中羟基自由基的掩蔽剂后，降解时间为60 min时样品Cu@CeO2-NaCl-PF对草酸根的降解率为10%，羟基自由基是样品Cu@CeO2-NaCl-PF降解草酸根的主要活性氧。【结论】 催化剂Cu@CeO2-NaCl-PF具有较大的比表面积、丰富的多级孔结构、高度分散的Cu活性位点以及较高含量的低价态金属离子，上述特性加速了气-液-固的三相传质过程，有助于O3在催化剂表面的富集，并提高了O3转化的速率；催化剂Cu@CeO2-NaCl-PF具有较高的循环使用稳定性，可以加速O3分解生成羟基自由基。
关键词： 氧化铈基铜催化剂； 多级孔结构； 草酸钠； 降解性能； 臭氧催化氧化
Abstract
Objective Sodium oxalate is a representative recalcitrant organic pollutant. To enhance its degradation performance， a hierarchically porous ceria-based copper catalyst is synthesized. The study investigated its catalytic ozonation mechanism， aiming to optimize ozone （O3） mass transfer efficiency thereby accelerating O3 decomposition into reactive oxygen species.
Methods A ceria-based copper catalyst was synthesized via spray-drying technique and salt-templated synthesis method， using NaCl as a salt template and phenolic resin （PF） as a shaping agent. Various samples were obtained by varying the NaCl and PF addition amounts under identical processing conditions. The micro-morphologies of all samples were characterized through X-ray diffraction （XRD） patterns， scanning electron microscopy （SEM） images， pore size distribution curves， and X-ray photoelectron spectroscopy （XPS） spectra. The degradation performance of various ceria-based copper catalyst samples for sodium oxalate in an aqueous solution was investigated， and the sample with the optimal degradation performance was identified. Using 5，5-dimethyl-1-pyrroline N-oxide （DMPO） as a trapping agent for hydroxyl radicals， the primary reactive species in the solution were detected by electron spin resonance （ESR）. The cycling stability of the optimal catalyst was studied through four repeated degradation experiments. Furthermore， the catalytic ozonation mechanism of the ceria-based copper catalysts was explored.
Results and Discussion Micro-morphological characterization of various samples indicated that catalyst particle size significantly increased with higher NaCl mass， whereas PF addition exhibited minimal influence on particle size. However， PF dosage substantially affected pore structure and specific surface area. Without PF addition， the salt template and metal oxides within the particles were insufficiently encapsulated， resulting in structural collapse after washing. Conversely， excessive PF led to an overly thick coating layer that impeded pore formation. With a NaCl-to-PF mass ratio of 1：1， the prepared sample Cu@CeO2-NaCl-PF exhibited an average particle size of approximately 35.3 nm， mesopore size of 5 nm-45 nm， and macropore size of 3 000 nm- 5 000 nm. The specific surface area ， mesopore volume， macropore volume， and total pore volume reached 52.15 m2/g， 0.240 mL/g， 4.778 mL/g， and 5.115 mL/g， respectively. The mass fractions of Cu0-Cu+ and Ce3+ were 67.1% and 18.7%， respectively. The sample Cu@CeO2-NaCl-PF demonstrated enhanced catalytic performance due to its larger specific surface area， multi-scale hierarchical porous structure， highly dispersed Cu active sites， and abundant low-valent metal ions. These structural advantages collectively promoted the gas-liquid-solid three-phase mass transfer， facilitating O3 enrichment on the catalyst surface while significantly accelerating the conversion rate. At a degradation time of 45 min， complete degradation （100%） of oxalate was achieved by sample Cu@CeO2-NaCl-PF. After the fourth cycle at a degradation time of 60 min， it maintained 95% degradation efficiency， with the residual concentrations of copper ions （comprising Cu0-Cu+ and Cu2+） in the solution measured at 0.23 mg/L ， 0.27 mg/L ， 0.34 mg/L ， and 0.37 mg/L sequentially across cycles， demonstrating exceptional recyclability at low leaching concentrations. Upon the addition of 1 mmol/L tert-butanol as a masking agent for hydroxyl radicals in the solution， the oxalate degradation rate of Cu@CeO2-NaCl-PF at 60 min was reduced to 10%， confirming hydroxyl radicals as the primary reactive oxygen species responsible for oxalate degradation. In contrast， when 1 mmol/L CCl4 was added as a masking agent for superoxide anions in the solution， its degradation rate exhibited only marginal reduction， indicating that superoxide anions were not directly involved in oxalate degradation. The sample Cu@CeO2-NaCl-PF was demonstrated to accelerate O3 decomposition， generating hydroxyl radicals.
Conclusion The catalyst Cu@CeO2-NaCl-PF is characterized by a relatively large specific surface area， a multi-scale hierarchical porous structure， highly dispersed Cu active sites， and abundant low-valent metal ions. These features collectively enhance the gas-liquid-solid three-phase mass transfer and promote ozone enrichment on the catalyst surface， thus accelerating O3 conversion efficiency. The catalyst Cu@CeO2-NaCl-PF exhibits excellent cycling stability and remarkable capability in facilitating O3 decomposition， generating hydroxyl radicals.
Keywords： ceria-based copper catalyst； hierarchical porous structure； sodium oxalate； degradation performance； catalytic ozonation
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