Cellulose is the most abundant source of organic carbon on earth. Its direct conversion to several platform molecules such as sorbitol, ethylene glycol, lactic acid, glucose etc� has been reported numerously in literature. The direct one-pot conversion of cellulose to n-hexane, however, is seldomly encountered and an efficient high yield one-pot process is highly desired, but lacking. Such selective and deep hydrodeoxygenation (HDO) requires an advance degree of tuning the many competitive reactions in a cascade fashion for making hexane without C-C breaking or forming.In this presentation, we present how high yields of liquid hydrocarbons directly from cellulosic feedstock can be achieved in a one-pot biphasic catalytic system.1 The catalytic reaction proceeds at elevated temperatures under H2 in presence of a soluble acid and a specifically modified Ru/C. The former is dissolved in the water phase and primarily responsible for cellulose hydrolysis while the tuned Ru/C, suspended in the organic phase, is in control of the catalytic hydrogenation and HDO activity. Under optimal conditions, cellulose is fully converted to more than 80% of liquid alkanes including n-hexane (over 50 % in yield), n-pentane, methylcyclopentane and cychohexane in a few hours. A study with several reaction intermediates shows that the catalytic route preferably proceeds via intermediate HMF to obtain liquid alkanes, while the route via sorbitol is less likely. Essential elements to obtain high liquid alkane yields are i) the controlled hydrolysis of cellulose, ii) the biphasic conditions, and most importantly, iii) the proper modification of the hydrogenation and HDO selectivities and activities of commercial Ru/C. The catalytic system is reusable and also capable of converting holocellulose in wood chips. [1] B. Op de Beeck et al. Submitted.

Direct, fast, and selective catalytic conversion of cellulose to n-hexane

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.