Carbonylation of Aryl Halide Catalyzed by Active-carbon Supported Ionic Liquid-phase Palladium Catalyst

Highly dispersed supported ionic liquid-phase palladium catalyst was prepared and its catalytic performances for carbonylation of aryl halide were investigated. Active-carbon supported ionic liquid-phase palladium catalyst was characterized by XRD, high-resolution TEM (HRTEM), and XPS. The results showed that the active-carbon supported ionic liquid-phase palladium catalyst was reduced to zero valence and that the average particle diameter of the Pd crystallites was less than 5 nm. A thin ionic liquid film was observed on the surface of the catalyst. The results indicated that the supported ionic liquid-phase palladium catalyst exhibited higher activity in the carbonylation of aryl halides compared with the corresponding organic-ionic liquid biphasic system. Under the optimum reaction conditions: 140 °C, pCO = 4.0 MPa, n(PhI):n(Pd) = 10528:1, the turnover frequency (TOF) of 4926 h−1 was achieved for ethyl benzoate with the conversion of 99.3%, and the selectivity for forming ethyl benzoate was more than 99%.