Controlled synthesis of dendritic ruthenium nanostructures under microwave irradiation and their catalytic properties for p-chloronitrobenzene hydrogenation

In this study, the shape-controlled synthesis of ruthenium (Ru) nanostructures was examined using microwave irradiation. Dendritic Ru nanostructures, with an average diameter of about 34.7 nm, were successfully synthesized when ruthenium chloride (RuCl 3 ) was reduced using a reducing agent of benzyl alcohol, in the presence of polyvinylpyrrolidone (PVP) under microwave irradiation for 360 s. By examining selected parameters affecting the shape-controlled synthesis of dendritic Ru nanostructures, i.e., the concentration of the RuCl 3 precursor, different reducing agents, molecular weight of PVP and the molar ratio of RuCl 3 /PVP, were identified as key factors affecting the successful synthesis of dendritic Ru nanostructures. The catalytic performance of obtained dendritic Ru nanostructures was evaluated for hydrogenation of p-chloronitrobenzene (p-CNB). High selectivity to p-chloroaniline (p-CAN) of about 99.58% was obtained using dendritic Ru nanostructure catalysts at 80 °C under 1 MPa hydrogen pressure, having a 72.81% conversion rate of p-CNB. The selectivity to p-CAN with a dendritic Ru nanostructure catalyst is notably higher than that of conventional 5% ruthenium/carbon catalysts (62.12%). Here in we demonstrate that synthesized dendritic Ru nanostructures present a promising catalytic performance in the hydrogenation of p-CNB, having potential applicability to a wide range of catalytic reactions.