Cellulose hydrogenolysis on a combination of tungsten oxide nanorods with and without ruthenium loading for enhanced ethanol selectivity

Abstract

The hydrolysis of cellulose to ethanol is still uneconomical with a low yield of this desired product; hence it is important to develop a promising multifunctional catalyst that can convert cellulose to selectively high yields of ethanol. Herein, an attempt has been made to synthesize ruthenium (Ru) loaded WO₃ nanorods, which will give a highly active catalytic surface with both the metal and support participating in the reaction to improve ethanol yields from 28.94% to 44.56%. WO₃ not only helps the C–C cleavage of glucose but also suppresses the isomerization of glucose so that no propanol is produced, and the selective yield of ethanol improves. The combined electronic properties of Ru^o and W⁶⁺ participate in enhancing the catalytic activity and increasing the cellulose conversion to ethanol. The bond functionality was also investigated by performing reactions with various reactants under the same reaction conditions. Based on the obtained reaction pathway, the kinetic parameters were calculated for the simplified reaction network and validated with the experimental values. The retro-aldol condensation reaction led by C–C cleavage of glucose to form glycolaldehyde was determined as the rate-limiting step. Cellulose conversion to ethanol using the combination of catalysts Ru/WO₃ and WO₃ in an integrated system was well-fitted with first-order kinetics.