Effect of Activation Degree of Resorcinol–Formaldehyde Carbon Gels on Carbon monoxide Tolerance of Platinum–Ruthenium Polymer Electrolyte Fuel Cell Anode Catalyst

Abstract

Resorcinol−formaldehyde carbon gels (RFCs) show several advantageous properties as a catalyst support over other carbons, as their pore volume and pore size can be readily tailored, for example, via CO 2 activation. In this study, RFCs were synthesized with various activation degrees (burn-off) as 0, 37, 58, and 88% and used as the support for a PtRu anode electrode; a commercial Pt 2 Ru 3 /C anode catalyst was used as a reference. The catalysts were characterized by powder X-ray diffraction (PXRD), BET surface area, transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). The performance and CO tolerance of the obtained catalysts were tested through single cell performance analysis with CO contaminations ranging from 100 to 2000 ppm. The prepared Pt 2 Ru 3 /RFC catalysts showed superior CO tolerance. Especially Pt 2 Ru 3 /RFC prepared using an RFC with a burn-off of 58% (RC1000Ac58) showed the highest performance and best CO tolerance. The activation degree could affect the volumes and sizes of mesopores and micropores, resulting in differences in size and dispersion of PtRu particles, and accessibility to the particles both of which govern the performance and CO tolerance of the catalysts. Pt 2 Ru 3 /RC1000Ac58 showed the highest cell voltage of 0.787 V and highest CO tolerance at 2000 ppm of CO (0.655 V, only 16.8% overvoltage). Supporting PtRu particles by using a carbon support with an optimum activation degree could be a practical method to improve the performance and CO tolerance of a PtRu electrocatalyst.

Characterization and performance evaluation of Pt Ru/C TiO2 anode electrocatalyst for DMFC applications

“…Otherwise, the absorbed intermediates (e.g., CO) bring about a kinetic obstacle by transforming electrochemically active areas into inactive areas through occupying the available spaces. In other words, alloying Pt and Ru as an anode electrocatalyst promotes the oxidation of CO to carbon dioxide (CO 2 ) and mitigates the problem of Pt poisoning [19]. However, using this anode electrocatalyst still does not yield the desired performance, electrocatalytic activity, and durability goals, especially when the lifetime of DMFC is considered.…”

Ligand effect of SnO2 on a Pt–Ru catalyst and the relationship between bond strength and CO tolerance

“…Weakening of the Pt-CO bond strength caused by the ligand effect contributes to CO tolerance; however, it is hard to evaluate the Pt-CO bond strength quantitatively in situ. Weakening of the Pt-CO bond strength often decreases HOR activity [27][28][29] in membrane electrode assemblies (MEAs), and CO tolerance is not improved in this case.…”

Evaluation of Novel Fuel Cell Catalysts with Ultra-Low Noble Metal Contents towards Electrochemical Catalysis

“…As a result, MOF represents the likelihood that the pores of different NPs will solidify. 90 The great porosity of the MOF system allows for the presence of additional chemicals in the NPs. Because of this, applications in heterogeneous catalysis, gas storage, and chemical sensing are particularly interesting for the NPs@MOF tool.…”

“…A generic scheme for the post-synthetic modification (PSM) of MOFs. 90 Degradation of the skeleton during particle production, etc. Obtaining NPs with cavity size matching, highly specified materials, well-defined gaps, and uniform size dispersion over the MOF matrix is thus not an easy operation, and careful selection of the suitable procedure to assure material mixing is required.…”