Pd Nanoparticle Supported on N‐Doped Carbon Derived from Sodium Alginate/Melamine Blends as Efficient Heterogeneous Catalyst for Heck Reactions

Abstract

AbstractN‐doped porous carbon shows great potential in the field of heterogenous supports due to its high porosity, large surface area, rich active sites, and strong chelation with catalytic active metals species. Herein, we successfully prepared a novel N‐doped porous carbon derived from sodium alginate/melamine blends (SAMNC) with different mass ratio through a simple carbonization and activation process. Hierarchical porous structure of the derived N‐doped carbon has been confirmed with the SEM, TEM, and N2 adsorption characterization. After Na2PdCl4 solution impregnation and further reduction process, Pd0 nanoparticles have been uniformly immobilized on the SAMNC support to produce novel Pd@SAMNC catalyst. The optimal Pd@SAMNC‐0.6 possesses a high N content (5.13%), Pd content (5.90%), large BET specific surface area of 1884.5 m2·g−1. Positron annihilation lifetime spectroscopy (PALS) investigation of the porous carbon materials provided the sub‐nano level microporous information proofs of Pd@SAMNC‐0.6 had the capability to provide more active sites for reactions than commercial Pd supported on activated carbon (Pd@AC). Pd@SAMNC‐0.6 catalyst showed superior catalytic efficiency in Heck coupling reaction between aromatic halides and alkenes and can be recycled for 17 runs without significant decrease in catalytic efficiency.