Abstract
Core–shell structured catalysts, made by placing either a monolayer or a thin layer of a noble metal on relatively cheap core-metal nanoparticles, are fascinating and promising fuel cell catalysts due to their high utilization of noble metals. Here, we report our development of a core–shell structured catalyst, Ru@Pt/C, generated by a novel and facile pulse electrochemical deposition (PED) approach. We demonstrate that compared with a commercial Pt/C catalyst, this novel catalyst achieves over four times higher mass activity towards the anodic oxidation of methanol, and 3.6 times higher mass activity towards the cathodic reduction of oxygen. Importantly, we find that the intrinsic activity of Pt in this Ru@Pt/C catalyst is doubled due to the formation of the core–shell structure. The catalyst also shows superior stability: even after 2000 scans, it still retains up to 90% of the peak current. Our findings demonstrate that this novel PED approach is a promising method for preparing high-performance core–shell catalysts for fuel cell applications.
Highlights
Low-platinum (Pt) catalysts, realized by either enhancing Pt utilization or reducing Pt loading and thereby decreasing its usage, have been one of the most interesting topics in proton exchange membrane fuel cell (PEMFC) research in the last decade[1,2,3,4]
Using these Ru/C nanoparticles as the core, we prepared a core–shell structured catalyst with high Pt utilization using a pulse electrochemical deposition method in which an ultra-thin Pt shell is deposited on the surface of Ru nanoparticles supported by carbon black; we designate this catalyst Ru@ Pt/C
We found that the turnover frequency (TOF) was more than double that of Johnson Matthey (JM)-Pt/C, revealing that the enhanced ORR performance of Ru@Pt/C resulted from the high Pt dispersion caused by the core–shell structure, and from the enhanced intrinsic activity of Pt, which in turn may have been due to the interaction between Pt and Ru, as well as the quantum effects arising from high Pt dispersion
Summary
Low-platinum (Pt) catalysts, realized by either enhancing Pt utilization or reducing Pt loading and thereby decreasing its usage, have been one of the most interesting topics in proton exchange membrane fuel cell (PEMFC) research in the last decade[1,2,3,4]. A few researchers in the last decade have employed pulse electrochemical deposition[16,17] to prepare fuel cell catalysts; this approach has received little attention because the catalysts generated by this method did not exhibit significant advantages, the particle size often was too large, and the size distribution was undesirable. Pulse deposition might be a good method for the preparation of shell layer of the core-shell structured catalyst, and further, that a few atoms shell layer on the core–shell catalyst might confer more stability than a monolayer. Based on these two ideas, we attempted to prepare core–shell catalysts with a shell of several atom layers by pulse electrochemical deposition, and we obtained exciting results. It should be mentioned that up to this point, we have not scoured the literature for research on core–shell catalysts prepared via this method
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.
