Selective production of acetol or methyl lactate from cellulose over RuSn catalysts

Designing a catalytic system that could convert cellulose to switchable C3 alcohols or esters with controllable selectivity is highly desired to meet the rapidly changing market demand.Herein,we develop RuSn catalysts with the altering Sn loadings that can achieve acetol formation from cellulose hydrogenation at240℃in presence of H_(2)or yield methyl lactate production from cellulose conversion in methanol and water mixture at 200℃in presence of N_(2).The increased Sn contents from 3%to 6%lead to form different surface sites from Ru_(3)Sn_(7),Ru,and SnO_(x)to Ru_(3)Sn_(7)and SnO_(x).The integrated Ru_(3)Sn_(7),Ru,and SnO_(x)species on 1.5%Ru-3%Sn/SiO_(2)catalyze isomerization,retro-aldol condensation,and hydrogenation individual steps with coordinated reaction rates,resulting in the acetol formation with a high yield of 53.7 C%.Furthermore,the optimum combination of Ru_(3)Sn_(7)and SnO_(x)on 1.5%Ru-6%Sn/SiO_(2)contributes to the isomerization,retro-aldol condensation,dehydration,and 1,2-hydride shift,giving rise to the preferential production of methyl lactate at a 25.1 C%yield.These results illustrate the feasibility of controlling the selective conversion of cellulose to C3 acetol or methyl lactate by devising a tunable catalytic system,which guides the rational design of catalysts for the selective conversion of cellulose.

One Pot Synthesis of Bio-Ethylene Glycol from Cellulose

In this study, various composite Ni-W2C/active carbon catalysts were synthesized. W2C was prepared by carbothermal hydrogen reduction. The metal loading of W2C in catalyst was 30 wt.%. Carbon was impregnated with metatungstate. It was dried at 120?C for 12 h. Carbon was then carburized in H2 flow, the temperature was increased from 25?C to 450?C, and then to 800?C and stayed for 4 h. The W2C/active carbon was treated with H2SO4 to create more function groups on the surface. Ni-W2C/active carbon was prepared by incipient-wetness impregnation method. After calcination and reduction processes in H2 flow, Ni-W2C/active carbon catalyst was obtained. The reaction of cellulose to ethylene glycol in one step was carried out in a batch reactor under the following condition: 1 g cellulose, 0.3 g catalyst, 100 ml H2O, 4 - 6 MPa H2, 220?C - 280?C, and 400 rpm. The reaction between cellulose and catalyst is a solid-solid reaction; therefore, the contact between these two solid materials is important. Long ball milling time would increase the contact between these two solids. The ball milling time and the functional groups on active carbon play important roles in this reaction. The results demonstrated that one pot synthesis of EG from cellulose is economically and technically feasible.