Carbon-supported Pd-Cr electrocatalysts for the electrooxidation of formic acid that demonstrate high activity and stability

In this paper, we first report that Pd-Cr alloy can be used as a catalyst for the anodic oxidation of formic acid (FAO). A series of carbon supported Pd-Cr alloy (Pd-Cr/C) catalysts with different Pd-Cr atom ratios was prepared with chemical reduction method. The PdxCr1−x/C catalysts (0.1 ≤ x ≤ 0.4) showed better performance toward the anodic oxidation of formic acid than Pd/C and Pt/C. Among them, Pd0.8Cr0.2/C (Pd/Cr = 8:2, atomic ratio) exhibits the highest catalytic activity. Compared with Pd/C catalyst, the potential of anodic peak of formic acid at the Pd0.8Cr0.2/C catalyst electrode shifted toward negative value by 50 mV. Pd0.8Cr0.2/C also exhibits high stability, suggesting that Pd0.8Cr0.2/C is a good candidate for the formic acid fuel cell. The characteristics of Pd0.8Cr0.2/C were correlated using X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and electrochemical measurements.