Methanol Electro-Oxidation on Carbon-Supported PtRu Nanowires

Abstract

One of the key objectives in fuel cell technology is to improve the alcohol oxidation efficiency of Pt-based catalysts. A series of carbon-supported PtRu nanowires with different concentrations of Pt and Ru were prepared for application in methanol oxidation in acid media. The physicochemical properties and electrocatalytic activity of these catalysts during methanol oxidation are function on their structure, morphology and composition. A Pt 60 Ru 40 /C catalyst shows the best behaviour towards methanol electro-oxidation allowing decrease the onset potential approximately 0.2 V respect to others PtRu/C synthesised nanowires. The structural modification of Pt by Ru and synergetic character of RuPt are main factors that could contribute to reduction of energy necessary for electro-oxidation process. The Pt and PtRu nanowires have different sizes and distribution on the substrate. The average crystallite sizes, found by XRD, are in the 4.6-5.9 nm range and the lattice parameter is between 0.3903-0.3908 nm. Small differences with the values of the Pt/C catalyst were found. The XPS results show a prevailing presence of metallic Pt and Ru 4+ species.

Fast Polymerization of Polydopamine Based on Titanium Dioxide for High-Performance Flexible Electrodes

“…The 4f 7/2 and 4f 5/2 peaks of Pt located at 71.5 and 74.8 eV, respectively. 47 The energy difference of 3.3 eV between the two peaks indicated Pt chelation on the surface of the PDA film. 48 3.4.…”

“…The high-resolution XPS spectra of Pt 4f orbits were divided into two characteristic peaks. The 4f 7/2 and 4f 5/2 peaks of Pt located at 71.5 and 74.8 eV, respectively . The energy difference of 3.3 eV between the two peaks indicated Pt chelation on the surface of the PDA film …”

Influência Da Composição Dos Nanofios Pt-Ir/C Na Atividade Catalítica Frente a Oxidação Eletroquímica De Etanol Em Meio Ácido

“…Os nanofios apresentam diâmetro médio de 4-5 nm e comprimento da ordem de 10-20 nm, Pode-se também observar a presença de nanopartículas nos catalisadores com maior proporção de Ir, indicando que este elemento não forma nanofios tão facilmente quanto a Pt, como já demonstrado anteriormente para nanofios de PtRu/C. 19,21…”

“…17 Estas características podem melhorar a sua utilização em diferentes aplicações, tais como eletrocatalisadores para sistemas de células a combustível para conversão de energia. [18][19][20][21] Recentemente, nanocatalisadores de Pt-Ir de diferentes morfologias, incluindo nanofios foram desenvolvidos e testados na reação de desprendimento de oxigênio. Os nanocatalisadores foram mais eficientes do que o catalisador Ir/C comercial e a atividade catalítica diminui com a proporção de espécies IrO x no mesmo.…”

DFT Study on Methanol Oxidation Reaction Catalyzed by PtmPdn Alloys

“…Furthermore, the strong adsorption of CO easily makes Pt poison, which will hinder the transfer of subsequent methanol molecules to the active site, resulting in sluggish reaction kinetics [7][8][9][10][11]. To decrease the Pt usage and improve the CO-poisoning tolerance, one appealing solution is the addition of other metal elements (such as Pd, Ru, Au, Ag, Mo, Co, Ni, Cu, and Sn) into PtM [12][13][14][15][16][17][18][19]. Among the pure metal catalysts, Pd is an effective catalyst for MOR, with a good catalytic capacity [20].…”