Mn-Ce复合氧化物微球的制备及其催化氧化甲苯性能

为了开发高效稳定、具有低温活性的降解VOCs催化材料，采用传统水热法制备了一系列不同锰铈比的催化剂(MnO₂、Mn_0.95Ce_0.05O_x、Mn_0.90Ce_0.10O_x、Mn_0.80Ce_0.20O_x及Mn_0.60Ce_0.40O_x)，利用SEM、BET、XRD、H₂-TPR、O₂-TPD、拉曼光谱等技术对催化剂的物理化学性质进行了表征分析，同时考察了其对甲苯的催化氧化活性。结果表明：通过简单的水热合成法合成出的Mn-Ce复合氧化物均为微球，但Ce的加入使得微球催化剂表面的纳米针消失，变为光滑的微球体；而不同的催化剂在氧化甲苯时呈现不同的催化氧化性能，其中Mn_0.80Ce_0.20O_x具有最佳的甲苯氧化性能，这是由于其具有较强的氧化还原性能、较高的化学吸附氧含量及存在Mn-Ce固溶体。因此，通过控制催化剂中Ce含量，可调控催化剂的形貌和物理化学特性，从而使Mn-Ce复合氧化物在甲苯催化氧化中展现出优异的催化性能。研究结果为新型高效降解VOCs催化材料的设计和开发提供了新思路。

Preparation of Mn-Ce composite oxide microspheres and their performance on toluene catalytic oxidation

In order to develop high-efficient, stable and low temperature active catalytic materials for VOCs degradation, a series of Mn-Ce catalysts with various Mn/Ce mole ratios (MnO2, Mn0.95Ce0.05Ox, Mn0.90Ce0.10Ox, Mn0.80Ce0.20Ox & Mn0.60Ce0.40Ox) were prepared by a traditional hydrothermal synthesis method. The physicochemical properties of these catalysts were characterized and analyzed by SEM, BET, XRD, H2-TPR, O2-TPD and Raman spectroscopy, and their catalytic oxidation of toluene was investigated. The results indicated that Mn-Ce composite oxides prepared by simple hydrothermal synthesis method were microspheres, while Ce addition caused the disappearance of the nano-needle borne on the catalyst surfaces and the formation of smooth microspheres. The catalysts with various Mn/Ce mole ratios exhibited different catalytic activity for toluene oxidation, of which Mn0.80Ce0.20Ox had the best performance, this was ascribed to its strong redox properties, high chemisorbed-oxygen content and the existence of Mn-Ce solid solution. Thus, the morphology and physicochemical properties of the catalysts could be regulated by controlling the Ce content, which enabled these Mn-Ce composite oxides to exhibit excellent catalytic performance in toluene oxidation. This study provided a new idea for the design and development of novel VOCs catalytic materials with high efficiency.