Preparation and catalytic performance of porous magnetically recyclable Fe3O4@ZIF-8@Cux/Pdy catalyst

Abstract

Magnetic catalysts are increasingly recognized for their potential in promoting efficient recycling processes. In this study, a series of Fe₃O₄@ZIF-8@Cu_x/Pd_y magnetic catalysts were fabricated through an environmentally - friendly synthetic route. The inclusion of Fe₃O₄ imparts robust magnetic properties to the catalysts, thereby facilitating their facile separation and recycling. Meanwhile, the ZIF-8 structure on the surface remarkably enlarges the specific surface area, providing more available reaction sites. The catalytic activity is predominantly ascribed to the Cu/Pd component, which functions as the active center. To investigate the microstructure and crystal structure of the catalysts, we employed various analytical techniques, including TEM, XRD, and XPS et al. The model reaction 4-nitrophenol (4-NP) reduction to 4-aminophenol (4-AP) was employed to assess the catalyst's performance. The results revealed that the optimal catalytic activity was achieved when the catalyst contained 0.1 mmol of Cu and 0.07 mmol of Pd, which the reaction was completed within merely 80 s, with a rate constant (k) of 0.0513 s⁻¹. This formulation not only demonstrated excellent catalytic performance but also held a distinct advantage in terms of convenient recyclability, which is of great significance for practical applications.