Weak base favoring the synthesis of highly ordered V-MCM-41 with well-dispersed vanadium and the catalytic performances on selective oxidation of benzyl alcohol

The key to improve the performance of heteroatom catalysts is to ensure the orderliness of catalysts and the good dispersion of heteroatoms. The alkalinity plays the indispensable role in synthetic process of V-MCM-41 catalyst. The excessive alkalinity of synthetic system will make the MCM-41 difficult to crystallize, even to dissolve. It is easy to accumulate for heteroatomic species in the system of low alkalinity. Herein, the highly ordered V-MCM-41 with high vanadic content in framework is synthesized in the condition of excessive NH3·H2O in this paper. A series of characterization results prove the good dispersion of vanadium species, and most of vanadium gets into the framework of MCM-41 with the states of tetravalence and pentavalence. Furthermore, the modified MCM-41 by other transition metals is successful synthesized by the method of V-MCM-41 in this paper. The V-MCM-41 shows well catalytic activity for the selective oxidation of benzyl alcohol, which up to 74.83% for the conversion of benzyl alcohol and 96.20% for selectivity of benzaldehyde when initial V/Si = 0.10. The paper provides the possibility for industrial application of V-MCM-41 in the oxidation of benzyl alcohol for benzaldehyde. Besides, the work provides a significant idea for the synthesis of modified MCM-41 by well-dispersed transition metals. The highly ordered V-MCM-41 with well-dispersed vanadium is synthesized in the condition of excessive NH3·H2O. The alkalinity plays an important role in synthetic system of V-MCM-41. MCM-41 will be dissolved in the system of excessive alkalinity, but too low alkalinity is not conducive to getting into framework of vanadium. The weak base can solve the above problems effectively. The maximum radio of initial V/Si reaches 0.25. A series of characterization results prove that most of vanadium atoms get into the framework. The V-MCM-41 shows well catalytic activity for the selective oxidation of benzyl alcohol, which up to 74.83% for the conversion of benzyl alcohol and 96.20% for selectivity of benzaldehyde when initial V/Si = 0.10. The paper provides the possibility of V-MCM-41 in industrial application to the prepare benzaldehyde. Meanwhile, the work provides a significant idea for the synthesis of modified MCM-41 with well-dispersed transition metals. [Display omitted]