Uncovering the role of BN3 species in BNC for metal-free catalytic reduction

A novel BNC material synthesized through controlled co-doping of boron and nitrogen in carbon exhibits excellent catalytic activity and recyclability in the metal-free catalytic reduction of nitrobenzene. The BN 3 species in the obtained BNC play a crucial role in catalytic activity. • A simple and controllable method for synthesizing boron and nitrogen co-doped carbon (BNC) materials has been developed. • BNC materials as metal-free catalysts have demonstrated environment-friendly features, outstanding reactivity, and stable performance in the catalytic reduction of nitrobenzene. • BN 3 species in BNC materials play a crucial role in catalytic activity and a controllable preparation of BN 3 species has been achieved. Carbocatalysts are considered a sustainable alternative to metal-based catalysts. By incorporating boron and nitrogen elements, the catalytic performance of carbon catalysts can be improved. Here, we report a simple and controllable method for synthesizing boron and nitrogen co-doped carbon (BNC) materials used for green catalytic reduction of nitrobenzene to aniline. By using boric acid as the boron source, guanidine hydrochloride as the nitrogen source, and citric acid as the carbon source to adjust the boron, nitrogen, and carbon content, controllable preparation of BN 3 species in BNC materials has been achieved. The experimental results confirm that BN 3 species play a crucial role in catalytic activity. When the content of BN 3 species is 5.3 %, the BNC material exhibits excellent catalytic activity and high selectivity in the reaction of nitrobenzene to aniline. Further theoretical calculations indicate that BN 3 species promote the adsorption and activation of nitrobenzene and hydrazine hydrate on the surface of BNC, thereby facilitating the catalytic reaction.