An efficient Brønsted acidic polymer resin for the carbonylation of formaldehyde to glycolic acid

In the present work, a series of sulfonic polymer-based acid catalyst PDS-x’s was obtained by hydrothermal method. The physical and chemical properties of the catalysts were characterized by X-ray diffraction, N 2 adsorption–desorption isotherms, thermogravimetric analysis, Fourier transform infrared spectrometer, pyridine-adsorbing IR, acid–base titration, X-ray photoelectron spectroscopy, and CHNS elemental analysis. The carbonylation of formaldehyde was chosen as a probe reaction to test the catalytic performance. The results show that the content of acid sites and specific surface area can be adjusted by changing the molar ratio of sodium 4-vinylbenzenesulfonate (SVBS) to divinylbenzene (DVB). The catalyst performance results show that the PDS-x’s can efficiently catalyze glycolic acid synthesis. And a high glycolic acid yield up to 96% was obtained on PDS-2.1 due to its large specific surface area, plentiful mesoporosity as well as suitable acid concentration. This data are even higher than those on super-strong CF 3 SO 3 H and commercial resin Amberlyst-15. Moreover, the carbonylation of formaldehyde is a structure-sensitive reaction, the isolated and monolayer dispersed -SO 3 H is much more active than aggregated −SO 3 H. Furthermore, the catalyst has high stability.