Kinetic Study of the Competitive Hydrogenation of Glycolaldehyde and Glucose on Ru/C with or Without AMT

The competitive hydrogenation of glycolaldehyde and glucose over 1% Ru/C catalyst was studied in a batch reactor at 373-403 K and 6 MPa hydrogen pressure, with or without the presence of ammonium metatungstate (AMT). It was found that the presence of AMT retarded significantly the hydrogenation of both aldoses, and this suppressing effect was more pronounced on the glucose hydrogenation. The hydrogenation of glycolaldehyde occurred always preferentially to the glucose hydrogenation, with or without the presence of AMT. The kinetic data in the absence of AMT were well modeled based on Langmuir-Hinshelwood-Hougen-Watson kinetics assuming the surface reaction being rate-determining and noncompetitive adsorption of dissociatively chemisorbed hydrogen and aldose. However, in the presence of AMT, the complexing between AMT and aldose and the strong adsorption of AMT on Ru surface must be considered in the development of new kinetic model. The as-modified model described the data satisfactorily. (c) 2014 American Institute of Chemical Engineers AIChE J, 61: 224-238, 2015