Abstract
Electrocatalytic activity of Pt and bimetallic PtRu nanoparticles (both Vulcan supported and unsupported) toward electrooxidation of dimethyl ether (DME), a potential small organic molecule fuel, in an acid medium (0.5 mol dm−3 H2SO4) has been significantly enhanced by dispersing them over a thin film of zirconia (ZrO2). The enhancement effects concern increases of the DME electrocatalytic current densities recorded under both cyclic voltammetric and chronoamperometric conditions. Similar effects have been observed for the oxidation of methanol. Regarding the dissimilar DME electrooxidation mechanisms at Pt and PtRu catalytic centers, the activating capabilities of zirconia seem to originate from the high population of reactive –OH groups favoring mobility of protons and the capability of inducing the oxidative removal of poisoning (CO-type) intermediates both at platinum and ruthenium catalytic sites. In the presence of the zirconia matrix, the onset potential for the oxidation of DME (particularly at PtRu) is shifted more than 50 mV toward less positive potentials. Mutual metal-support interactions are also postulated.
Highlights
There has been growing interest in low-temperature fuel cells [1,2,3,4,5,6,7] during recent years, and the hydrogen-oxygen fuel cell is technologically the most advanced and the most commonly considered for practical purposes
While the degree of dispersion and the electrochemically active surface area of the Vulcan-supported nanoparticles are superior, relative to the pristine metal catalysts, the studies involving later (Vulcan-free) systems permit more undisputable verification of the influence of zirconia on the activity of Pt and PtRu during the dimethyl ether (DME) oxidation. It is apparent from the results obtained that the electrocatalytic current densities for the DME oxidation have increased upon dispersing Pt and PtRu catalysts onto nanostructured zirconia matrices
To get more information about the electrocatalytic performance of pristine Pt nanoparticles, relative to those deposited onto the zirconia matrix, during prolonged electrochemical measurements, additional current-time measurements were performed upon application of the constant potential of 0.54 and 0.44 V (Fig. 6 b and c)
Summary
There has been growing interest in low-temperature fuel cells [1,2,3,4,5,6,7] during recent years, and the hydrogen-oxygen fuel cell is technologically the most advanced and the most commonly considered for practical purposes. We consider hybrid electrocatalytic systems (for DME oxidation) utilizing nanostructured zirconia (ZrO2) matrices (layers) for dispersing two types of model distinct catalytic metal nanoparticles (Pt and PtRu) both in the pristine (unsupported) form and supported onto carbon (Vulcan) carriers.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
