Catalytic and Electrochemical Study of Cu-ZSM-5/MCM-41

Hierarchically structured micro-mesoporous ZSM-5/MCM-41 composite materials incorporating copper ions were synthesized using pre-synthesized ZSM-5 and cetyltrimethylammonium bromide (CTAB) as a template for forming the MCM-41 structure. The composites were characterized through powder X-ray diffraction, N₂ adsorption-desorption, diffuse reflectance spectroscopy (UV-vis DRS), Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and energy dispersive X-ray spectroscopy. X-ray diffraction confirmed well-ordered ZSM-5 and MCM-41 structures, and UV-vis DRS showed successful copper ion incorporation. N₂ adsorption-desorption revealed the presence of both microporous and mesoporous structures. To evaluate their catalytic performance, Cu-incorporated ZSM-5/MCM-41 composite catalysts were assessed through the oxidation reaction of ethylbenzene using tert-butyl hydroperoxide (TBHP) as the oxidizing agent. With a 9% (w/w) Cu-ZM-5 (5 wt % copper-incorporated ZSM-5/MCM-41) catalyst and an oxidant to ethylbenzene molar ratio of 2:1 at 40 °C in the absence of a solvent for 4 h, the process yielded acetophenone (93.2%) as the major product. Additionally, these Cu-incorporated composites were examined as electrode materials for electrochemical storage. Cyclic voltammetry and galvanostatic charge-discharge studies showed that Cu-ZM-5 exhibited pseudocapacitive behavior, with a capacitance of up to 366 F g^-1 at a current density of 1 A g^-1, surpassing ZSM-5 and ZSM-5/MCM-41. These results highlight Cu-ZM-5's potential as an effective electrode material for electrochemical storage applications like supercapacitors.