Nonthermal Plasma-Modified Carbon-Carrying Sn-Based Ternary Nanocatalyst for High-Performance Direct Dimethyl Ether Fuel Cells

A Vulcan XC72 carbon-supported Sn-based ternary metal catalyst (Pt₃Pd₃Sn₂/C) is reported to have yielded the highest specific power density (90 mW mg⁻¹_PGM) as compared with other catalysts tested for direct dimethyl ether (DME) fuel cells. However, the micropores present in Vulcan XC72 limit fuel utilization by causing Pt agglomeration. Vulcan XC72 composed of nongraphitized carbon species is also prone to corrosion. Therefore, herein, carbon supports such as multiwalled carbon nanotubes (MWCNT), black pearl 2000 (BP2000), and their cold N₂ plasma-treated counterparts are tested to further enhance the activity of the catalyst and systematically describe the comparative advantages over the Vulcan XC-72 carbon. Electroanalytical tests show that Pt₃Pd₃Sn₂/BP2000 exhibit excellent performance in terms of electrochemical active surface area, peak current density, and DME oxidation charge. A beneficial effect of plasma activation on the activity is observed only in the case of MWCNT while having no or negative effect on the other carbons. Laboratory fuel cell test indicates that Pt₃Pd₃Sn₂ nanoparticles supported on optimized binary carbon support containing 75% plasma-activated MWCNT and 25% BP2000 (Pt₃Pd₃Sn₂/75M25B) provides the highest reported power density of 117 mW mg⁻¹_PGM at 70 °C fuel cell temperature and ambient pressure.