Alcohol electro-oxidation on platinum-ceria/graphene nanosheet in alkaline solutions

Platinum/graphene nanosheet and platinum-ceria/graphene nanosheet are prepared by a one-pot synthesis protocol and examined as electrocatalysts for the oxidation of methanol, ethanol, ethylene glycol, and glycerol in alkaline solutions. The activity of the catalysts is evaluated by cyclic voltammetry, linear sweeping voltammetry, and chronoamperometric tests. It is indicated that the addition of ceria is favorable for the oxidation of the alcohols. The platinum-ceria/graphene nanosheet catalyst exhibits higher current densities and superior durability in comparison with the platinum/graphene nanosheet. Maximum current densities of 1.1, 1.3, 3.2 and 2.5 A mg(-1) Pt are obtained from the platinum-ceria/graphene nanosheet catalyst for the oxidation of methanol, ethanol, ethylene glycol, and glycerol, respectively. Notably, the current density values for the oxidation of ethylene glycol (3.2 A mg(-1) Pt) and glycerol (2.5 A mg(-1) Pt) are among the most active electrocatalysts reported in the literature. The activity of the catalysts in 1 M KOH solution is compared with that in 1 M H2SO4 solution. Both the platinum/graphene nanosheet and platinum-ceria/graphene nanosheet show superior performance in alkaline media. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.