Rastegarpanah Ali, Deng Jiguang, Liu Yuxi, Jing Lin, Pei Wenbo, Wang Jia, Dai Hongxing
Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
J Environ Sci (China). 2025 Jan;147:617-629. doi: 10.1016/j.jes.2023.04.005. Epub 2023 Apr 15.
The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO and MnSO·HO for MnO and Co(NO)⋅6HO and CoCl⋅6HO for CoO). Bamboo-like MnO⋅CoO (B-MnO⋅CoO (S)) was derived from repeated hydrothermal treatments with CoO@MnO and MnSO⋅HO, whereas CoO@MnO nanorods were derived from hydrothermal treatment with CoO nanorods and KMnO. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn and Mn) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO⋅CoO (S) > CoO@MnO > MnO > CoO, matching the changing trend in activity. Among all the samples, B-MnO⋅CoO (S) showed the preeminent catalytic performance for the oxidation of toluene (T = 187°C, T = 276°C, and T = 339°C). In addition, the B-MnO⋅CoO (S) sample also exhibited good HO-, CO-, and SO-resistant performance. The good catalytic performance of B-MnO⋅CoO (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO⋅CoO (S) proceeds through the adsorption of O and toluene to form O*, OH*, and HC(CH)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO and HO. The findings suggest that B-MnO⋅CoO (S) has promising potential for use as an effective catalyst in practical applications.
采用水热法，使用不同的金属前驱体（MnO 用 KMnO₄ 和 MnSO₄·H₂O，CoO 用 Co(NO₃)₂·6H₂O 和 CoCl₂·6H₂O）制备了锰钴混合氧化物纳米棒。竹节状 MnO₂·Co₃O₄（B-MnO₂·Co₃O₄ (S)）由 Co₃O₄@MnO₂ 和 MnSO₄·H₂O 进行重复水热处理得到，而 Co₃O₄@MnO₂ 纳米棒由 Co₃O₄ 纳米棒和 KMnO₄ 进行水热处理得到。研究表明，氧化锰在晶体结构中为四方晶系，而氧化钴为立方晶系。锰表面离子存在多种氧化态（如 Mn²⁺ 和 Mn³⁺）以及表面氧缺陷。吸附氧物种的含量和低温还原能力按 B-MnO₂·Co₃O₄ (S) > Co₃O₄@MnO₂ > MnO₂ > Co₃O₄ 的顺序下降，与活性变化趋势相符。在所有样品中，B-MnO₂·Co₃O₄ (S) 对甲苯氧化表现出卓越的催化性能（T₉₀ = 187°C，T₉₅ = 276°C，T₉₉ = 339°C）。此外，B-MnO₂·Co₃O₄ (S) 样品还表现出良好的抗 H₂O、CO₂ 和 SO₂ 性能。B-MnO₂·Co₃O₄ (S) 的良好催化性能归因于高浓度的吸附氧物种和良好的低温还原能力。甲苯在 B-MnO₂·Co₃O₄ (S) 上的氧化过程是通过 O₂ 和甲苯的吸附形成 O₂*、OH* 和 HC(CH₃)* 物种，然后这些物种反应生成苯甲醇、苯甲酸和苯甲醛，最终转化为 CO₂ 和 H₂O。研究结果表明，B-MnO₂·Co₃O₄ (S) 在实际应用中作为有效催化剂具有广阔的应用前景。
