Effects of Polyethers on the Chitosan-Pd (II) Gel Beads Catalysts Prepared by a Co-Precipitation Method

Abstract

The effects of polyethers (polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol copolymer (PEG-PPG-PEG) and polyethylene glycol (PEG)) on the chitosan (CS)-Pd (II) gel beads catalysts prepared by a co-precipitation method have been studied. The blending of the polyethers led to an acceleration effect of the sol–gel transition. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results showed that most of the blended polyethers component was efficiently, selectively, dissolved by water, but, unexpectedly, no pore structure was obtained. It was found that the blending of the polyethers can promote better phase dispersion of the Pd species in the CS matrix. The extracted CS/PEG-PPG-PEG/Pd gel beads catalysts had higher catalytic performance than extracted CS/PEG/Pd or CS/Pd gel beads catalysts alone due to its better phase dispersion of Pd⁰ species and stronger intermolecular interactions.

Keywords:

• chitosan
• co-precipitation
• gel beads
• heterogenous catalysis

Funding

The authors acknowledge the financial support from the National Natural Science Foundation of China (grant number: 21203123), and the Academic Climbing Project for the Youth Academic Leader of Zhejiang Province, China (grant number: PD 2013391).