Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation

Abstract

Carbon-supported bimetallic Pt-Co cathode catalysts have been previously identified as higher activity alternatives to conventional Pt/C catalysts for fuel cells. In this work, a series of Pt-Co/C catalysts were synthesized using electroless deposition (ED) of Pt on a Co/C catalyst prepared by modified charge enhanced dry impregnation. X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) characterization of the base catalyst showed highly dispersed particles. A basic ED bath containing PtCl 6 2´a s the Pt precursor, dimethylamine borane as reducing agent, and ethylenediamine as stabilizing agent successfully targeted deposition of Pt on Co particles. Simultaneous action of galvanic displacement and ED resulted in Pt-Co alloy formation observed in XRD and energy dispersive X-ray spectroscopy (XEDS) mapping. In addition, fast deposition kinetics resulted in hollow shell Pt-Co alloy particles while particles with Pt-rich shell and Co-rich cores formed with controlled Pt deposition. Electrochemical evaluation of the Pt-Co/C catalysts showed lower active surface but much higher mass and surface activities for oxygen reduction reaction compared to a commercial Pt/C fuel cell catalyst.

Synthesis and Characterization of Platinum and Platinum based Alloy Nanoparticles Anchored on Various Carbon Materials for Methanol Oxidation in a DMFC – A Short Review

“…Therefore, efforts are being made in the recent years to reduce this interaction between graphene nanosheets by introducing some other conducting material in order to use the unique properties of graphene. Although a lot of research work was carried out using the above-mentioned support materials for Pt and Pt based bi-metallic or tri-metallic nanomaterials, the research on the use of hybrid materials is limited [122,[132][133][134]. Very recently CuPt alloy nanoparticles assembled on rGO, Vulcan XC-72 (VC) and their hybrid (rGO-VC) were studied by Yilmaz et.…”

Unraveling Oxygen Electrocatalysis Mechanisms on a Thin-Film Oxygen-Deficient Perovskite La0.6Sr0.4CoO3−δ

“…Conventional methods for electrochemical data analysis generally tend to focus on a narrow range of the kinetic current domain describing the electrochemical process, such as the Tafel or the linear segments of typical polarization curves. 19 However, in most instances, the polarization curves are distorted by diffusion processes, the reverse reaction, and coupling effects of other reactions. Therefore, to analyze the experimental data from such a system, a full physicsbased model with multiple kinetic reactions is needed.…”

“…Similar to particle size and distribution, the specific surface area of a powder critically determines the activity of a catalytic process . We employed a Brunauer–Emmett–Teller (BET) technique, using a Micromeritics ASAP 2020 surface-area analyzer, for surface-area analysis under N 2 atmosphere with a low relative pressure ( P / P 0 ) range 0.01–0.1 (0.01, 0.03, 0.06, 0.08, 0.10) to obtain the specific surface areas of the synthesized LSCO-1000 powder.…”

“…The stable, steady-state laminar flow conditions created adjacent to a RDE, by rotation, minimize mass transport limitations, thus allowing the attainment of information about electrode reaction kinetics. ,, The RDE method is favorable compared to other methods because it is one of the few convective systems for which the equations of fluid mechanics have been rigorously solved for steady-state conditions, and it is simple to construct and easy to use. , In addition, it has the advantages of having stable and easy-to-compute limiting currents and kinetic data that are obtainable over relatively large potential regions beyond the open-circuit potential, and both the anodic and cathodic reactions can be studied with a suitable choice of electrode material . The majority of publications, to date, have focused on a “classical” Levich or Koutecky–Levich analysis of the linear sweep voltammetry (LSV) and cyclic voltammetry (CV) data, but the major drawback of this method of analysis is the inability to analyze multistep reactions. ,− …”

Synthesis of Highly Active Pd@Cu–Pt/C Methanol Oxidation Electrocatalysts via Continuous, Co-Electroless Deposition

“…Thus, analyses and performances of materials are based on average bulk compositions instead of true metal ratios at the bimetallic particle scale. To solve this, electroless deposition (ED) has been used to selectively deposit the second metal only on the surface of a pre-existing primary metal by catalytic activation of a reducing agent on the primary metal surface [ 10 , 13 , 15 , 16 , 17 , 18 , 19 , 20 ]. This process ensures that the secondary metal is deposited only on the primary metal and not on the support [ 15 ].…”