Glycerol electrooxidation on carbon-supported Pt-CuO and PtCu-CuO catalysts

J. M. SIEBEN; A. E. ALVAREZ; M. D. SÁNCHEZ

Ciudad Autónoma de Buenos Aires

Simposio; VIII Symposium on Hydrogen, Fuel Cells and Advanced Batteries; 2022

International Association for Hydrogen Energy and Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires

The growing global production of glycerol from biodieselmanufacture has sparked renewed interest in the developmentof low-temperature fuel cells powered by this alcohol.Glycerol is the main by-product (10 % by weight) generatedduring the transesterification process of vegetable oils andfats in biodiesel plants. In addition, it is non-toxic, easy tohandle, store and transport, and possesses high volumetricenergy density (i.e., 6.26 kW h L-1).Among the different types of fuel cells, anion exchangemembrane fuel cells (AEMFCs) fed with aqueous solutionsof ethanol or glycerol have emerged as promising powersources to supply clean energy for portable, stationary, andperhaps even automotive applications because of the fastelectrode kinetics, the lower corrosion of the cell componentsin an alkaline environment and the possibility of usingnon-noble catalysts in the cathode, when compared to proton-exchange membrane fuel cells (PEMFCs). However, theactivity and performance of the anodic catalyst must be enhanced,and the platinum-group-metal (PGM) loading in theelectrode must be reduced to make them a cost-competitivealternative technology to batteries. Several strategies havebeen implemented to boost the performance of platinumcatalysts, including designing particles with controllableshape and structure, allowing with non-precious metals orcombination with metal oxides, and employing different catalystsupports. In this respect, we have paid particular attentionin this work to the addition of metal oxide promoters toenhance the catalytic activity and long-term stability of Ptand PtCu electrocatalysts for the oxidation of glycerol in alkalinemedium. A recent investigation showed that the presenceof spinel oxide NiCo2O4 nanoparticles onto a three-dimensionalhierarchically porous graphene-like carbonboosts the catalytic activity of platinum toward glycerolelectrooxidation [1]. Garcia et al. determined that MnOx actsas a source of labile oxygenated species, which facilitate theoxidation of glycerol on PtAg/MnOx/C electrocatalysts [2].Whereas, Li and coworkers found that YOx/MoOx decorationof ultrathin platinum nanowires enables the brake of the CCbonds of ethanol and glycerol and also improves the anti-CO poisoning ability of the catalytic sites [3]. Velázquez-Hernándezet al. found that the presence of Ni(OH)2 in a platinumcatalyst favors the electrooxidation of glycerol to glycolateand mesoxalate via the bifunctional mechanism [4].Herein, we synthesized Pt and Pt0.7Cu0.3 catalysts supportedon hybrid CuO/C materials with different CuO contents.The as-prepared electrocatalysts were characterizedby XRD, HR-TEM, EDX, ICP-OES, and XPS. The experimentsshowed that the presence of CuO boosts the activity and stabilityof Pt and PtCu particles in the electrooxidation of glycerolin alkaline environment. The current density of themost active catalyst was found to be 1.73 A mgPt-1, which is ca. 3 times higher than that of Pt/C.References1 B.-C. Liu, S.-L. Chen, X.-Y. Ling, Q.-X. Li, C.-W. Xu, Z.-L. Liu, Highactivity of NiCo2O4 promoted Pt on three-dimensional graphene-like carbon for glycerol electrooxidation in an alkalinemedium, RSC Advances, 10 (2020) 24705.[2] A.C. Garcia, E. B. Ferreira, V.V. Silva de Barros, J.J. Linares, G.Tremiliosi-Filho, PtAg/MnOx/C as a promising electrocatalystfor glycerol electro-oxidation in alkaline medium, Journal ofElectroanalytical Chemistry, 793 (2017) 188-196.[3] M. Li, Z. Zhao, W. Zhang, M. Luo, L. Tao, Y. Sun, Z. Xia, Y. Chao,K. Yin, Q. Zhang, L. Gu, W. Yang, Y. Yu, G. Lu, S. Guo, Sub-MonolayerYOx/MoOx on Ultrathin Pt Nanowires Boosts AlcoholOxidation Electrocatalysis, Advanced Materials, 33 (2021)2103762.[4] I. Velázquez-Hernández, M.T. Oropeza-Guzmán,] M. Guerra-Balcázar, L. Álvarez-Contreras, N. Arjona, Electrocatalytic Promotionof Pt Nanoparticles by Incorporation of Ni(OH)2 forGlycerol Electro-Oxidation: Analysis of Activity and ReactionPathway, ChemNanoMat, 5 (2019) 68-78.