Development of a sustainable and recyclable oxC60–Ly@Fe GCE electrode: an eco-friendly catalyst for electrochemical sulfonation to synthesize benzenesulfonic acids

Abstract

In this study a reusable and environmentally benign catalyst, oxC₆₀–Ly@Fe, was rationally designed and synthesized. The catalyst's efficacy and performance were systematically evaluated in the electrosynthesis of chlorobenzenes 1(a-l) and S₈2(a) derivatives, enabling the synthesis of benzenesulfonic acid derivatives 3(a–i) under mild reaction conditions, specifically at ambient temperature, a current density of 15 mA, and a reaction time of 1 hour, with urea/ChCl serving as the electrolyte. This electrochemical process afforded excellent product yields ranging from 87% to 95%. Key electrochemical catalytic metrics, including the E-factor, atom economy, turnover number (TON), and turnover frequency (TOF), were calculated, demonstrating the process's environmental compatibility and superior catalytic performance. The catalyst is thoroughly characterized (FT-IR, XRD, SEM, EDX/EDS, TGA, XPS, CV, BET), and the products are confirmed by melting point, NMR, and CHN analyses.