Methanobactin-mediated synthesis of bimetallic Au-Pd/AlO toward an efficient catalyst for glucose oxidation.

A green bioreductive approach with methanobactin was adopted to fabricate bimetallic Au-Pd/AlO catalysts for solvent-free oxidation of glucose to gluconic acid with HO at atmospheric pressure. The catalyst was characterised by diffuse reflectance UV-vis spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction techniques to understand synergistic interactions between Au and Pd. Effects of Au to Pd molar ratio on the catalytic activity of Au-Pd/AlO were investigated. The Au-Pd/AlO catalyst with Au/Pd molar ratio of 0.8:0.2 exhibited excellent catalytic performance. With the catalyst, the oxidation activities of glucose to gluconic acid 2856 mmol min g and selectivity 99.6% were attained at 323 K with HO. The results indicated the activity and selectivity was affected by the ratio of Au/Pd on the AlO. The formation of AuPd/AlO was favourable for the catalytic reaction.