Investigation of PtCoCr/C catalysts for methanol electro-oxidation identified by a thin film combinatorial method

The ternary Pt–Co–Cr system was investigated for suitability as a methanol electro-oxidation reaction (MOR) catalyst by combinatorial synthesis and high-throughput screening method. A PtCoCr thin film library was prepared by a multi-target sputtering technique while parallel characterization was performed using a multichannel multielectrode analyzer. The highest MOR activity was observed in the Pt30Co30Cr40 composition after a conditioning process. The high MOR activity of the thin film Pt30Co30Cr40 composition was verified in a powder version of the alloy. In 20 h chronoamperometry tests, the MOR activity of the Pt30Co30Cr40 powder catalyst alloy was 10.3 A gnoble metal−1, which was 160% higher than the 4.03 A gnoble metal−1 value of the PtRu/C catalyst, suggesting that PtCoCr alloys are promising candidates as Ru-free MOR catalysts. The effect of the conditioning process was also investigated, revealing that dissolution and oxidation of surface Co and Cr occurs during conditioning. After conditioning, the activity of 900 °C reduced Pt30Co30Cr40 catalyst dramatically increased by 26.8 times from 0.0765 to 2.13 A gcat.−1 at 600 s of the chronoamperometry tests.