Methanol-Tolerant Oxygen Reduction Reaction at Pt–Pd/C Alloy Nanocatalysts

Abstract

Carbon-supported platinum and Pt–Pd alloy electrocatalysts with different Pt/Pd atomic ratios were synthesized by a microemulsion method at room temperature (metal loading is 10 wt %). The Pt–Pd/C bimetallic catalysts showed a single-phase fcc structure and the mean particle size of Pt–Pd/C catalysts was found to be lower than that of Pt/C. The methanol-tolerant studies of the catalysts were carried out by activity evaluation of oxygen reduction reaction (ORR) on Pt–Pd catalysts using a rotating disk electrode (RDE). The studies indicated that the order of methanol tolerance was found to be PtPd3/C>PtPd/C>Pt3Pd/C. The oxygen reduction activities of all Pt–Pd/C were considerably larger than that of Pt/C with respect to onset and overpotential values. The Pd-loaded catalysts shift the onset potential of ORR by 125 mVMSE, 53 mVMSE, and 41 mVMSE to less cathodic potentials for Pt3Pd/C, PtPd/C, and PtPd3/C, respectively, with reference to Pt/C and the Pt3Pd/C catalyst showed greater shift in the onset value than the other PtPd catalysts reported in literature. Moreover, the Pt–Pd/C catalysts exhibited much higher methanol tolerance during ORR than the Pt/C, assessing that these catalysts may function as a methanol-tolerant cathode catalysts in a direct methanol fuel cell.

Anchoring Effect of Exfoliated-Montmorillonite-Supported Pd Catalyst for the Oxygen Reduction Reaction

“…The durability of the cathode catalyst for the oxygen reduction reaction (ORR) is one of the primary roadblocks hindering the commercialization of proton exchange membrane fuel cells (PEMFC). , Currently, carbon black (i.e., Vulcan XC72 materials) supported Pt catalysts are the most commonly used, state-of-the-art catalysts for PEMFC. − Unfortunately, the carbon supports do not meet the long-term durability requirements for PEMFC. For example, under fuel cell operating conditions, the Pt/C catalysts are subject to high electrode potential changes in the O 2 atmosphere.…”

Experimental and DFT study of thiol-stabilized Pt/CNTs catalysts

“…Currently, the Pt/C catalyst with highly dispersed Pt nanoparticles (NPs, 2-5 nm) supported on carbon is widely employed as the state-of-the-art commercial catalyst. [6][7][8][9][10] The poor durability of the Pt/C catalyst is marked by a rapid and significant loss of platinum electrochemical surface area (ECSA) over time due to the corrosion of carbon support and Pt dissolution, Ostwald ripening, and aggregation during fuel cell operation. 11,12 The degradation of Pt/C catalysts is illustrated in Fig.…”

Carbon-Supported Pt-Based Alloy Electrocatalysts for the Oxygen Reduction Reaction in Polymer Electrolyte Membrane Fuel Cells: Particle Size, Shape, and Composition Manipulation and Their Impact to Activity

“…Interestingly, using Pd as the second metal in PtM/C catalyst was found not only to enhance the ORR activity but also to increase the catalyst's methanol tolerance. 259,260 Among various carbon-supported PtM nanoparticle alloy catalysts, core−shell structured alloy catalysts with M or PtM alloy as the core and Pt as the shell have been found to exhibit considerably higher performance for the ORR than pure Pt/C. Strasser's group 261,262 has synthesized a series of core−shell structured PtM/C (M = Co, Cu) catalysts with PtM alloy as the core and Pt as the shell through a dealloying process.…”

“…Using electrochemical dealloying, Strasser's group also studied a series of PtM 3 /C systems with different metals as the second alloy elements (M = Cu, Co, and Ni). 259 They examined the composition of PtM 3 using EDS (energy dispersive spectroscopy), XPS (X-ray photoelectron spectroscopy), and ICP-MS (inductively coupled plasma-mass spectroscopy; see Table 8) and found that the dissolution of 3d metals resulted in compositional changes. The degree of dealloying of Pt−Co and Pt−Ni binary systems was lower than that of Pt−Cu compounds, as evidenced by the presence of around 15−20 at.…”