(560z) Catalytic Conversion of Glucose to Tartaric Acid over Au-Pt/TiO2 Catalysts

Replacing fossil-based feedstocks with renewable resources is considered to be key for reducing carbon emission and environmental pollution. Catalytic conversion of biomass to fuels and chemicals is very important for establishing environment-friendly chemical processes. Aqueous phase oxidation of bio-derived sugars is crucial for sustainable conversion of biomass to value-added carboxylic acids and derivatives.¹ Tartaric acid (TA) has been widely used for additives of food, dyes and pharmaceuticals. Traditionally, TA is mainly synthesized via oxidation of Maleic anhydride, a two-step reaction generating significant amounts of toxic substances and waste products.² Up to date, there is no detailed study being reported for selective oxidation of sugars to TA using heterogeneous catalysts. Therefore, we proposed AuPt/TiO₂ catalyst for facile TA synthesis (50%) from glucose in base-free conditional 100 °C 10 bar O₂.

In this context, we systematically studied the transformation of TiO₂ crystalline phases to explore the strong Metal-Support Interaction for enhanced oxidation performances. It is found that AuPt nanoparticles supported pure anatase TiO₂ and a mixture of anatase and rutile phases have shown relatively better activity (conversion:100%) for glucose oxidation compared with pure rutile TiO₂(conversion:<70%). As revealed by literature survey, it is believed that O vacancy and the phase junctions between anatase and rutile provide the activity sites for oxidation reactions.³ The influence of particle size, as well as metal-metal and metal-support interaction on catalyst performances will be presented in this work. The outcome of this study will provide insights into rational design of effective metal catalysts for oxidation of sugars to value-added chemicals.

Reference

1. Derrien, E. et al. Aerobic Oxidation of Glucose to Glucaric Acid under Alkaline-Free Conditions: Au-Based Bimetallic Catalysts and the Effect of Residues in a Hemicellulose Hydrolysate. Industrial & Engineering Chemistry Research 56, 13176-13190, doi:10.1021/acs.iecr.7b01571 (2017).
2. Xuan, J. & Feng, Y. Enantiomeric Tartaric Acid Production Using cis-Epoxysuccinate Hydrolase: History and Perspectives. Molecules (Basel, Switzerland) 24, doi:10.3390/molecules24050903 (2019).
3. Zhang, J., Xu, Q., Feng, Z., Li, M. & Li, C. Importance of the relationship between surface phases and photocatalytic activity of TiO2. Angewandte Chemie-International Edition 47, 1766-1769, doi:10.1002/anie.200704788 (2008).