Synthesis and characterization of biowaste-derived porous carbon supported palladium: a systematic study as a heterogeneous catalyst for the reduction of nitroarenes

In this study, we present a green synthesis approach for the fabrication of porous carbon supported palladium catalysts derived from Caesalpinia pods. The synthesis involves self-activation of Caesalpinia pods in a nitrogen atmosphere at various temperatures (600 °C, 800 °C, and 1000 °C) to produce porous carbon nanoparticles. Among the synthesized carbon materials, the sample CP-CNS/10 synthesized at 1000 °C exhibited the highest surface area of 793 m²/g with an average pore size diameter of 1.8 nm. The resulting porous carbon material served as an efficient support for palladium nanoparticles, with a low metal loading of about 0.2 mol% Pd for the reaction. This catalyst demonstrated excellent performance in the reduction of nitroarenes to their corresponding aromatic amines. The successful incorporation of approximately 4.5% Pd during the deposition process highlights the potential of the porous carbon supported palladium catalyst synthesized at 1000 °C for a sustainable and efficient heterogeneous catalyst for the reduction of nitroarenes.