Selective glucose oxidation to organic acids over synthesized bimetallic oxides at low temperatures

Oxidation of glucose was investigated over bimetallic oxide catalysts with H 2 O 2 at 70–90 °C in ethanol and water under atmospheric pressure. Bimetallic oxides, contain Zn, Ce, Al, Mg, Sr and Fe were synthesized with co-precipitation methods. Screening of these oxides were proceeded in ethanol and the most effective one was tested in a more natural solvent water for 6 h. Effects of crystal structure, calcination, metal loading, reaction time and temperature on catalytic activity and product selectivities were investigated. Glucose conversion reactions were also performed with and without O 2 source as comparison. The most active and selective catalyst in ethanol at 70 °C was found as Mg–Al–cal (62% glucose conversion and 10.2% formic acid selectivity). Metal loadings (Cu/V) to Mg–Al–cal lowered the catalytic activity significantly. Mg–Al–cal, tested in water at 90 °C, provided almost 95% of organic acid (formic and acetic acid) selectivity with 38% conversion. Deactivation of Mg–Al–cal by product adsorption was also investigated by the addition of formic acid in ethanol at 70 °C. In the presence of formic acid, the catalyst exhibited 50% of glucose conversion and 78% of total organic acid selectivity (levulinic acid + lactic acid + formic acid) without using O 2 source. Graphical abstract