Porous organic polymer-supported palladium catalyst for hydroesterification of olefins

Abstract Hydroesterification of olefins with alcohols and CO is an attractive approach to synthesize value-added carboxylic esters. The current manufactures are mainly based on the use of homogeneous catalytic systems, and developing a heterogeneous process enabling cost-effective catalyst separation is of potential interest, particularly for higher olefins. In this contribution, we reported a robust porous organic polymer-supported palladium catalyst that exhibited excellent hydroesterification performance approaching that of the homogeneous counterpart. In addition, the catalyst shows remarkable adaptability for a broad range of substrates (both olefins and alcohols) and recyclability. The catalysts are thoroughly characterized by a spectrum of characterization techniques including N2 sorption, SEM, TEM, HAADF-STEM coupled with elemental mapping, FTIR with CO probe, XPS, and solid-state 31P NMR. Based on these, the good catalytic performance can be attributed to the high surface area, highly dispersed active metal species, and the strong coordination bonds between palladium center and the exposed phosphorous ligands in Porous organic polymer (POPs) frame. The ICP-OES and hot filtration test further indicate that the reaction truly proceeds in a heterogeneous manner, thus exhibiting great potential for industrial applications.