A series of core-shell Co-MOF-74@Mn-MOF-74 samples with different shell thicknesses were prepared by the seed growth method, which were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy, nitrogen adsorption-desorption and scanning electron microscopy (SEM). The shell thickness of these MOF samples were successfully controlled by adjusting the mass ratio between MnCl₂·4H₂O and Co-MOF-74. On this basis, these MOFs were applied to the catalytic oxidation of toluene. The results showed that with the growth of Mn-MOF-74 in the outer layer of Co-MOF-74, the oxidative selectivity of the substrate to benzaldehyde was greatly improved for the synergy between the core layer and shell layer. The conversion of toluene was 22.4%, and the selectivity of benzaldehyde was 98.1%. In addition, the catalyst can transform various substituted toluene into the corresponding aldehydes in highly selectivity and still keep good stability after four catalytic cycles. The selectivity of the corresponding aldehyde is generally above 80%.

采用种子生长法，制备了一系列不同壳厚的核-壳Co-MOF-74 @ Mn-MOF-74样品，并用粉末X射线衍射（PXRD），热重分析（TGA），归纳法表征。耦合等离子体质谱法（ICP-MS），X射线光电子能谱，氮吸附-解吸和扫描电子显微镜（SEM）。通过调节MnCl ₂ ·4H ₂之间的质量比，成功地控制了这些MOF样品的壳厚度O和MOF-74。在此基础上，将这些MOF应用于甲苯的催化氧化。结果表明，随着Co-MOF-74外层中Mn-MOF-74的生长，底物对苯甲醛的氧化选择性大大提高，从而促进了核层与壳层之间的协同作用。甲苯的转化率为22.4％，苯甲醛的选择性为98.1％。另外，该催化剂可以高选择性将各种取代的甲苯转化为相应的醛，并且在四个催化循环后仍保持良好的稳定性。相应醛的选择性通常高于80％。