铝蜂窝负载锰基催化剂的制备及其在室温下去除低含量甲醛的性能

采用水热共沉淀法和原位氧化还原法制备MnO_x/MgAl类水滑石(Mg₃Al₁-LDHs)催化剂，以水玻璃作为黏结剂将其负载到铝蜂窝上，用于室温下去除甲醛。通过X射线衍射(XRD)、热重分析(TG)、X射线光电子能谱(XPS)、N₂吸附-脱附、傅里叶变换红外光谱(FT-IR)等手段进行表征。表征结果表明：MnO_x/Mg₃Al₁-LDHs具有典型类水滑石结构，大量结合水和羟基； MnO_x为δ-MnO₂和Mn₃O₄的混合物，具有高比例Mn⁴⁺/Mn³⁺和丰富的吸附氧。实验结果表明：室温(25 ℃，相对湿度60%)下反应4 h后，MnO_x/Mg₃Al₁-LDHs催化剂可将甲醛质量浓度由1.30 mg/m³降至0.10 mg/m³以下，且经过8次和连续15 d实际测试，表明催化剂具有良好的稳定性和甲醛去除效果。MnO_x/Mg₃Al₁-LDHs催化剂最佳负载量(质量分数)为5%，风扇最佳功率为10 W，空气中湿度对甲醛去除效果影响较小，该催化剂具有较强水分抵抗能力，反应温度提升会较大程度提高甲醛去除效果。

Preparation of Manganese-Based Catalyst Supported by Aluminum Honeycomb and Its Removal Performance for Low Content Formaldehyde at Room Temperature

The MnO_x/Hydrotalcites (Mg₃Al₁-LDHs) catalyst was prepared by hydrothermal co-precipitation method and in situ redox method. The catalyst was fixed on an aluminum honeycomb using sodium silicate as an adhesive for formaldehyde removal at room temperature. The removal performance of the catalyst was characterized by means of X-ray diffractometer (XRD), thermogravimetric analysis (TG), X-ray photoelectron spectroscopy (XPS), N₂ adsorption-desorption and Fourier transform infrared spectroscopy (FT-IR). The results show that MnO_x/Mg₃Al₁-LDHs presents the typical hydrotalcite-like structure with a large quantity of water and hydroxyl groups attached on the surface, and MnO_x is a mixture of δ-MnO₂ and Mn₃O₄ with a high proportion of Mn⁴⁺/Mn³⁺ and abundant adsorbed oxygen. The experiment results show that the MnO_x/Mg₃Al₁-LDHs catalyst supported by aluminum honeycomb can reduce the mass concentration of formaldehyde from 1.30 mg/m³ to below 0.10 mg/m³ after 4 h reaction at room temperature (25 ℃, relative humidity 60%), and its formaldehyde removal performance remains nearly unchanged after 8 times of actual testing for 15 consecutive days, thus proving that the catalyst has excellent stability and formaldehyde removal ability. During the experiment, the optimum mass fraction of the catalyst is 5%, the optimal fan power is 10 W, and air humidity has little effect on the removal of formaldehyde, indicating that the catalyst has strong moisture resistance, and the increase of reaction temperature can greatly improve the formaldehyde removal effect of the catalyst.