Sol–Gel Synthesis of Ruthenium Oxide Nanowires To Enhance Methanol Oxidation in Supported Platinum Nanoparticle Catalysts

Abstract

A template-directed, sol–gel synthesis is utilized to produce crystalline RuO2 nanowires. Crystalline nanowires with a diameter of 128 ± 15 nm were synthesized after treating the nanowires at 600 °C in air. Analysis of these nanowires by X-ray powder diffraction revealed the major crystalline phase to be tetragonal RuO2 with a small quantity of metallic ruthenium present. Further analysis of the nanowire structures by high-resolution transmission electron microscopy reveals that they are polycrystalline and are composed of interconnected, highly crystalline, nanoparticles having an average size of ∼25 nm. Uniform 3 nm Pt nanoparticles were dispersed on the surface of RuO2 nanowires using an ambient, solution-based technique yielding a hybrid catalyst for methanol oxidation. Linear sweep voltammograms (LSVs) and chronoamperometry performed in the presence of methanol in an acidic electrolyte revealed a significant enhancement in the onset potential, mass activity, and long-term stability compared with analogous Pt nanoparticles supported on commercially available Vulcan XC-72R carbon nanoparticles. Formic acid oxidation LSVs and CO stripping voltammetry revealed that the RuO2-supported Pt nanoparticles exhibit significantly higher CO tolerance, which leads to higher catalytic stability over a period of several hours. X-ray photoelectron spectroscopy results suggest that crystalline RuO2 leads to less-significant oxidation of the Pt surface relative to more widely studied hydrous RuO2 supports, thereby increasing catalytic performance.

Green synthesis of doped Co3O4 nanocatalysts using organic template for fast azo dye degradation from aqueous environment

“…Various chemical regents, surfactants and chemical reducing agents are used in the synthesis of metal oxides at a nanoscale with minimum agglomeration. [19][20][21] To eliminate the utilization of costly chemicals and release of hazardous reducing and stabilizing agents into the ecospheric region, in the work presented here, Co 3 O 4 , Co 3 O 4 :NiO and Co 3 O 4 :PdO/Pd nanocatalysts were synthesized using a cost effective and efficient bio-template, prepared with phytochemicals of Abies pindrow Royle (A. pindrow) leaves. Previously, we have successfully demonstrated the functionalization of metal oxide nanomaterials using Euphorbia cognata Boiss for energy storage applications.…”

“…There are numerous strategies for improving the efficiency of metal oxide photocatalysts such as metal oxide nanomaterials and doped metal oxides possessing novel characteristics 2,12,17,18 . Such methods enhance the photocatalytic ability of the synthesized materials by tailoring the optical properties and by introducing oxygen vacancies on the surface, which then consequently prevent the recombination of charge carriers 19 . However, synthesis of metal oxide nanomaterials and doped metal oxides at a nanoscale with minimum agglomeration is still a challenging task.…”

Pt–RuO u –SnO v /CMK-3 composite electrocatalysts for the methanol oxidation reaction

“…Besides, methanol is considered the most electroactive alcohol fuel. Therefore, direct methanol fuel cells (DMFCs) play an important role in addressing the future energy crisis [2,3]. The DMFC reaction involves the transfer of six electrons and produces CO 2 , H 2 O, and electricity.…”

“…The DMFC reaction involves the transfer of six electrons and produces CO 2 , H 2 O, and electricity. CO is the major reaction intermediate that tends to be adsorbed, blocking active sites of the anode (over the platinum catalyst) where methanol oxidation reactions (MORs) have taken place [3][4][5]. Significant effort has been devoted to address this poisoning phenomenon [4,6,7].…”

“…Significant effort has been devoted to address this poisoning phenomenon [4,6,7]. Pt-based bimetallic catalysts (often ruthenium, Ru) are considered the ideal alloy composition providing catalytic synergy to improve both power density and stability for methanol electro-oxidation [3,4,8,9]. Adsorbed -OH species, generated on Ru at the platinum/ruthenium edge by water dissociation, promote CO oxidation and thus enhance tolerance against poisoning [1,2,10,11].…”