One-pot synthesis of a carbon supported bimetallic Cu–Ag NPs catalyst for robust catalytic hydroxylation of benzene to phenol by fast pyrolysis of biomass waste

Abstract

The production of phenol in high yield and selectivity by direct catalytic hydroxylation of benzene (HOB) is challenging. In this study, a carbon supported bimetallic Cu–Ag NPs composite was synthesized (Cu–Ag/C) via one-pot fast pyrolysis of Cu–Ag preloaded sawdust. Characterization of the product using various techniques illustrated that Cu and Ag NPs were monodispersed on the biochar, which were obtained during the fast pyrolysis of biomass. The as-synthesized Cu–Ag/C efficiently catalyzed the HOB reaction, resulting in the production of phenol. The maximum yield of phenol was 34.9%, whereas the selectivity for phenol was 96% at 50 °C. The experimental results using various solvents at different retention times incorporated with GC/MS, ESR, and H2-TPD determinations suggested that ˙OH radicals played a dominant role in the catalytic HOB reaction, where Cu and Ag offered a synergistic interaction. This study may provide a new avenue for the preparation of catalysts and offer insight into the synergistic interaction of bimetallic catalytic HOB reactions.