Green bio‐based synthesis of starch-halloysite hybrid: An efficient heterogeneous catalyst for C–C coupling reactions

Using halloysite nanoclay (Hal) as support and its multi-functionalization, Pd@Hal-SA, containing amine‐functionalized starch with Cl-halloysite nanoclay, followed by coordination of Pd (II) acetate Pd@Hal-SA. The catalyst was characterized by using SEM/EDS, FTIR, XRD, BET, ICP-AES, TGA and DTGA. It was used as a novel heterogeneous catalyst for coupling reactions under mild reaction condition. The comparison of the catalytic activity of Pd-Hal(the catalyst without SA), Pd-SA (the catalyst without Hal)and Pd@Hal-SA confirmed the superior performance of the latter, indicating the contribution of two components, SA and Hal to the catalysis. Moreover, the catalytic activity of Pd@Hal-SA was higher than that of Pd@Hal+SA, implying that the use of hybrid system was more efficient that use of individual components in a separated form, due to the synergism between SA and Hal. The catalyst could be successfully recycled for several consecutive reaction times with slight loss of the catalytic activity.