Innovative functionalization of Vulcan XC-72 with Ru organometallic complex: Significant enhancement in catalytic activity of Pt/C electrocatalyst for the methanol oxidation reaction (MOR)

Abstract

In this work, a novel procedure to enhance the catalytic activity of Pt/C for the MOR by promoting surface Pt–Ru metal interactions is proposed. Vulcan is functionalized with home-prepared ruthenium (II) arene compound [(η6-C6H5OCH2CH2OH)RuCl2]2 (Ru-dim) and labeled CRu-dim. Then, Pt/CRu-dim is synthesized by the polyol method. Also, Vulcan functionalized with RuCl3·XH2O (Ru-com) and non-functionalized Vulcan are used to prepare Pt/CRu-com and Pt/C, respectively. The results show that functionalization with Ru-dim maintains the electronic sp2 hybridization of the graphitic segment of Vulcan. Physicochemical characterization strongly suggests the formation of Pt–Ru alloyed phases at Pt/CRu-dim: XRD shows about 50% Ru alloyed, while XPS indicates a shift of 0.32eV toward higher BE of Pt0. Such Pt–Ru interactions enhance the performance of Pt/CRu-dim for the MOR in acid media by reaching a current density of 45.0mAcm−2, two-fold increase compared to Pt/C. Moreover, the on-set potential of 0.25V determined for Pt/CRu-dim is 0.14V more negative relative to Pt/C. In summary, Pt/CRu-dim shows enhanced catalytic properties for Direct Methanol Fuel Cells (DMFCs) applications.