In-situ fabrication of Ag nanoparticles on biomass derived biochar as highly active catalyst for the halogenation of terminal alkynes at room temperature

Abstract Herein, we reported a facile and novel Ag nanoparticle (NP) catalyst fabricated on renewable biomass derived biochar through a facile in-situ reduction-pyrolysis process. In the absence of reductants or stabilizing agents, the oxygen-containing groups in original lignocellulosic biomass offer the requisite sites (–OH, –COOH, C-O-C) for in-situ reduction of Ag+ and anchor the metal center, which is conducive to synthesize uniformly dispersed Ag nanoparticle. The Ag@C catalyst was further applied to the conversion of 1-alkynes and N-halosuccinimide (-Cl, -Br and -I) to 1-haloalkynes of diverse structures with good to excellent yields up to 98% at room temperature. The catalyst showed broad substrate applicability and good recyclability. Extensive studies indicated that homogeneously dispersed Ag(0) particles were key to the high efficiency. Experimental and theoretical calculations also revealed that the addition of base could significantly activated the inert C-Cl bond in N-chlorosuccinimide, promoting its conversion at room temperature. The current finding offers a facile and economic method for the fabrication of nano metal catalysts on biomass derived carbon, further demonstrating the feasibility of utilizing the rigid structure and functionalities of biomass to prepare the carbonaceous material for catalysis applications.