(24c) 1,6-Hexanediol Synthesis from Cellulose

1,6-hexanediol (HDO) is a high value commodity chemicals ( $4,400/ton) used as a polyester or polyurethane component traditionally produced from adipic acid. In this presentation we discuss a three step catalytic route to produce HDO from cellulose¹ that includes: i) hydrolysis/dehydration of cellulose into LGO and HMF with sulfuric acid, ii) hydrogenation/hydrogenolysis of LGO and HMF into THFDM over Pd/Si-Al₂O₃  ²and iii) hydrogenolysis of THFDM into HDO over a bifunctional Pt-acid catalyst. The overall HDO yield is 50%. In this presentation we will discuss the catalytic chemistry of each of these steps and elucidate the relationship between the catalyst structure and performance. We use cellulose, white birch and corn stover as feedstocks.

The THFDM is converted into 1,2,6 hexanetriol and then HDO in the final step through a dehydration-hydrogenation mechanism on a bifunctional Pt-based catalysts in over 90% HDO selectivity (70% HDO yield). We will show that the active catalytic acid phase for the dehydration, a Brønsted acid site, is generated on the oxophilic support through hydrogen spillover from the Pt.

 

Reference:

1 J. He, K. Huang, K. J. Barnett, S. Krishna, D. M. Alonso, Z. J. Brentzel, S. P. Burt, T. Walker, W. F. Banholzer, C. T. Maravelias, I. Hermans, J. A. Dumesic and G. W. Huber, Faraday Discuss., 2017.

2 S. H. Krishna, D. J. McClelland, Q. A. Rashke, J. A. Dumesic and G. W. Huber, Green Chem., 2017, 19, 1278–1285.