Production of ethylene glycol from direct catalytic conversion of cellulose over a binary catalyst of metal-loaded modified SBA-15 and phosphotungstic acid.

Shitao Yu,Qiong Wu,Xincheng Cao,Lu Li,Shiwei Liu

doi:10.1039/c8ra03806f

Shitao Yu, Qiong Wu + Show 3 more

Open Access

https://doi.org/10.1039/c8ra03806f

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Journal: RSC advances	Publication Date: Jan 1, 2018
Citations: 18	License type: CC BY 3.0

Affiliation: Qingdao University of Science and Technology

Abstract

This study presents the utilization of a binary catalyst composed of metal-loaded modified SBA-15 (M/SBA-15) and phosphotungstic acid (H3PW12O40) for ethylene glycol (EG) production from direct catalytic conversion of cellulose. M/SBA-15 (M = Ru, Au, Pd, Pt, Rh and Ni) catalysts were prepared using the impregnation method and characterized by means of XRD, N2 physisorption, TEM and H2-temperature-programmed reduction (H2-TPR) techniques. Their catalytic performance was then studied in detail on the basis of cellulose conversion and the selectivity of polyols and EG. The results showed that the mesoporous structure of the SBA-15 sample was well maintained after the metal-loaded modification, and almost all of the selected catalysts gave about 100% conversion of cellulose. However, the selectivity for EG was greatly different. Among the various binary catalysts, the combination of Rh/SBA-15 and H3PW12O40 gave the best selectivity to EG (55.5%), whereas the worst selectivity of EG (11%) was obtained over the Au/SBA-15 and H3PW12O40 system under identical conditions. In addition to phosphotungstic acid, other W compounds were also studied in combination with the Ru/SBA-15 catalyst. The results showed that the EG selectivity depended on the W compounds as follows: H4SiW12O40 < H2WO4 < H3PW12O40. Therefore, the binary catalyst of Rh/SBA-15 and H3PW12O40 showed the greatest potential for EG production from direct catalytic conversion of cellulose.

Highlights

The excessive consumption of fossil fuel and the ever-increasing emissions associated with their consumption have spurred a great deal of research for alternative energy sources.[1]
We evaluated the catalytic performances of various binary catalysts of M/SBA-15 (M 1⁄4 Ru, Au, Pd, Pt, Rh and Ni) mesoporous materials and different W compounds and chose the best binary catalyst to produce ethylene glycol (EG) from the catalytic conversion of cellulose
Our results indicate that the binary catalyst of Ru/SBA-15 and TPA achieve higher EG selectivity than that obtained in a previous report

Summary

Introduction

The excessive consumption of fossil fuel and the ever-increasing emissions associated with their consumption have spurred a great deal of research for alternative energy sources.[1]. Zhang et al used the traditional active carbon (AC) as support for dispersing Ni particles to improve the activity of the catalyst in the catalytic conversion of cellulose to EG.[14] the AC had large surface area, the active sites exhibited low dispersion and poor accessibility. The microporous carbon used as support may have a negative effect on the overall catalytic performance due to its steric hindrance and diffusion limitations. For this reason, mesoporous carbon (CMK-3) with WCx active sites was synthesized to catalyze cellulose.[15] The WCx/CMK-3 catalyst exhibited better catalytic performance than the WCx/AC catalyst due to its good accessibility and the dispersion of the active sites.

Materials

Preparation and characterization of catalysts

Catalytic cracking cellulose

Catalyst characterization

Catalytic performance of the M-SBA-15 and H3PW12O40 binary system

The effect of reaction conditions on the distribution of main products

Conclusion