Heteroatoms-containing graphene oxide and reduced graphene oxide as catalysts for the oxygen reduction reaction.

E. PASTOR; A. M. BAENA; R. J. RIZO; N. MONGE; J. C. CALDERÓN; L. M. RIVERA; G. A. PLANES, ; G. M. MORALES

Lanzarote

Conferencia; GRAPHEsp2014; 2014

Polymer electrolyte membrane fuel cells (PEMFCs) have been considered as one of the most promising energy conversion technologies with the potential to reduce pollutant emissions and dependence on fossil fuels. However, this technology needs improvements before PEMFCs can successfully compete with conventional technologies. The fundamental reactions occurring inside a FC are hydrogen oxidation reaction and the oxygen reduction reaction (ORR) at the anode and cathode, respectively. For these reactions, nanostructured Pt-based materials supported on carbonaceous materials are needed but they are prohibitively expensive for making commercially viable FCs, in particular the ORR which requires at the cathode high Pt loading.The development of new synthetic methods of carbon-based nanostructures, in combination with the research efforts in the nonprecious metal and metal free catalysts, opened new opportunities to design cathodes materials which catalyze efficiently the ORR. For graphene, the substitution of carbon by its neighbors in the periodic table, or the covalent bonding of functional moieties containing those heteroatoms can modify its electronic structure, hydrophobic character, and chemical affinity, providing a way to tailor the catalytic properties. In this context, the most studied graphene derivatives are the graphene oxide (GO) and its reduction product reduced graphene oxides (RGO), which can be chemically modified by using several methods.In this work we report the recent efforts on the synthesis and characterization of heteroatoms (N, S and P) doped graphene-based materials as catalysts in the ORR. As starting material we used GO, RGO and carbon nanoribbons. The RGO was obtained by hydrothermal treatment of GO at 90, 150, 200 and 300 °C. These materials were characterized by FTIR, Raman, AFM, EDS-SEM and XPS. Finally, electrochemical experiments were made in order to establish the catalytic properties basic media, being the phosphorous doped GO material who displayed the best activity towards the ORR.Financial support from MINECO (Spain) and MINCYT (Argentina) (Projects PRI-AIBAR-2011-1307 and CTQ2011-28913-C02-02, FONCYT-PICT-2011-1701 and CONICET-PIP 2010-2012 GI, respectively) are gratefully acknowledged.