Polyoxometalate supported on silica-cobalt ferrite: As an efficient catalyst for the synthesis of benzimidazoles

Abstract

In this work, synthesized a new nanocatalyst (CoFe₂O₄@SiO₂-PW) by anchoring Kegging-type polyoxometalate (H₃PW₁₂O₄₀) on the silica-cobalt ferrite nanoparticles. Cobalt ferrite nanoparticles were covalently modified with 3-aminopropyltriethoxysilane (APTES) to provide the hybrid catalyst, followed by polyoxometalate anchoring onto the cobalt ferrite nanoparticles. To give the hybrid catalyst, cobalt ferrite nanoparticles were covalently modified with 3- aminopropyltrimethoxysilane, followed by polyoxometalate anchoring onto the cobalt ferrite nanoparticles. The new catalyst, CoFe₂O₄@SiO₂-PW was characterized using FT-IR, TG, XRD, SEM, EDX, TEM, BET, and VSM. The CoFe₂O₄@SiO₂-PW has been used as an efficient catalyst for the fabrication the benzimidazole derivatives. Furthermore, the catalyst can be easily reused seven consecutive times and recovered in the production of benzimidazoles without noticeable leaching of W and Fe and noticeable change in activity, demonstrating the nanocatalyst's chemical stability.