Er/β-zeolite-catalyzed one-pot conversion of cellulose to lactic acid

• DOI: 10.1007/s10934-016-0306-9
• Publication Date: 2016-11-01T05:46:14Z
• Authors: Fen-Fen Wang; Hai-Zhen Wu; Hui-Fang Ren; Chun-Ling Liu; Chun-Li Xu; Wen-Sheng Dong
• Keywords: 01 natural sciences; 0104 chemical sciences

Various Er/β-zeolite catalysts were prepared by grafting erbium species in aqueous solutions of erbium chloride onto β-zeolites. The catalysts were characterized using X-ray fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy, N2 physical adsorption, powder X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and NH3 temperature-programmed desorption. These catalysts were evaluated in the one-pot hydrothermal conversion of cellulose to lactic acid. Lactic acid yields of approximately 58 % were obtained using an erbium grafted on de-aluminated β zeolite (Er/deAlβ-2) with an erbium content of 12.4 wt% and a Si/Al ratio of 159:1. In catalyst recycling tests, the lactic acid yield decreased from 57.9 % in the first cycle to 51.2, 49.8 and 49.6 % in the second, third and fourth cycles, respectively. The decreases in catalytic activity during recycling are proposed to arise mainly from a combination of erbium ion leaching, deposition of carbon species in the zeolite pores and the partial structure collapse.