Abstract
Conversion of glucose to high-valued chemicals is one of the important routes for biomass utilization. Gold and aluminum modified SBA-15 molecular sieve catalysts(Au-Al/SBA-15) were prepared for aerobic oxidation of glucose. The active site-catalytic performance relationship was investigated. The structures of Au-Al/SBA-15 catalysts with different Au and Al contents were characterized by means of solid-state nuclear magnetic resonance( NMR) in combination with other techniques. It was found that four-coordinated Al is generated on SAB-15 and Au mainly exists in form of metallic state. The supported Au can be stabilized by four-coordinated Al, resulting in smaller Au particles on SBA-15. The interaction between Au and Al species promotes glucose oxidation, while the extra-framework Al species causes the side reaction and lower selectivity to gluconic acid. The role of NaOH in the reaction was revealed by C-13 solid-state NMR experiments, it benefits desorption of gluconic acid molecules from the catalyst surfa