Complex Dynamic during the oscillatory electro-oxidation of glucose on platinum

Understanding mechanistic details of the electrocatalytic oxidation of glucose is important from both fundamental and applied perspectives. Glucose is an abundant and environmentally friendly carbohydrate and generate 24 electrons in its complete oxidation. The objective of this work was to investigate the catalytic activity of Pt towards the electro-oxidation of glucose, in acidic and alkaline medium, exploring the oscillatory kinetics and its implications in practical systems. The very rich oscillatory dynamics observed under galvanostatic regime has been characterized. High amplitude potential oscillations (0.5 to 0.9 V), Figure 1(a), were observed in acidic and alkaline media and the periodic oscillation between high and low potential values may represent a self-cleaning process for the catalytic surfaces. However, potential oscillations in acidic media are unstable, whereas in alkaline media are very stable and have long duration. This process allows the oxidation of strongly adsorbed intermediates at each potential oscillation cycle and increases the power density of practical conversion systems of chemical to electrical energy c.f. Figure 1(b).