High-activity PtRuPd/C catalyst for direct dimethyl ether fuel cells

Dimethyl ether (DME) has been considered as a promising alternative fuel for direct-feed fuel cells but lack of an efficient DME oxidation electrocatalyst has remained the challenge for the commercialization of the direct DME fuel cell. The commonly studied binary PtRu catalyst shows much lower activity in DME than methanol oxidation. In this work, guided by density functional theory (DFT) calculation, a ternary carbon-supported PtRuPd catalyst was designed and synthesized for DME electrooxidation. DFT calculations indicated that Pd in the ternary PtRuPd catalyst is capable of significantly decreasing the activation energy of the C-O and C-H bond scission during the oxidation process. As evidenced by both electrochemical measurements in an aqueous electrolyte and polymer-electrolyte fuel cell testing, the ternary catalyst shows much higher activity (two-fold enhancement at 0.5 V in fuel cells) than the state-of-the-art binary Pt₅₀Ru₅₀/C catalyst (HiSPEC 12100). DME oxidation: Guided by DFT calculation, a ternary carbon-supported PtRuPd catalyst was designed and synthesized for dimethyl ether (DME) electrooxidation. The new Pt₄₆Ru₄₄Pd₁₀/C led to a two-fold enhancement in the performance of a direct DME fuel cell (DDMEFC). This allowed the DDMEFC performance to slightly surpass the performance of the state-of-the-art direct methanol fuel cell (DMFC).