The Contribution of Carbon Supports on the Activity of Pt for Glycerol Electrooxidation: the Importance of Investigating the Derivative Voltammogram and Arrhenius Plots

摘要

Glycerol electrooxidation was evaluated on Pt electrodeposited over carbon Vulcan (CV), multi-walled carbon nanotubes (MWCNTs), graphene oxide nanoribbons (GONRs), and graphene nanoribbons (GNRs). Different masses of Pt were deposited under the same conditions, producing different surface areas of Pt. The presence of GNRs slightly enhanced the specific activity of the catalyst. By investigating the derivative voltammetry of glycerol, we found that the supports did not shift the onset potential towards lower values. Moreover, we found that the apparent activation energy did not vary by changing the carbon support. In this sense, we rationalized the slight improvement in specific activity of Pt deposited on GNRs as a consequence of the frequency of collision factor due to the availability of Pt over the longitudinal flat surface of nanoribbons, as shown by the high active surface area/mass of electrodeposited Pt ratio.