PtNi/C catalysts

Several approaches to the designing of efficient electrocatalysts for the electrooxidation of ethanol have been reported. Some of them focused on the structure of the catalytic particles. For instance, by generating high-index faceted Pt particles, the catalytic activity and selectivity to COg of Pt/C can be improved.The same is true for PtNi/C catalysts.However, high-index planes are not stable in nanoparticles, hence the mass activity of those catalysts is low. Most studies, however, deal with bimetallic particles, typically Pt-M (M = W, Pd, Rh, Re, with PtSn... 

In addition to Pt—Au/C catalysts, several other Pt-based alloy catalysts, such as PtCo/C, PtNi/C, PtV/C, and PtPd/C were also reported, and the mechanism of enhancing ORR activity was investigated using both RDE and RRDE techniques. The mechanism of ORR improvement by alloying is ascribed to (1) increase in the catalyst surface roughness,(2) decrease in the coverage of surface oxides and an enrichment of the Pt-active sites of the catalyst surface,(3) increase in the d-orbital vacancy, which strengthened the Pt—O2 interaction, and (4) decrease in the Pt—Pt distance and the Pt—Pt coordination numbers. Table 7.4 lists the properties of PtCo/C and PtNi/C catalysts and their ORR performance parameters measured by RDE techniques for comparison. 

Table 7.4. Summary of the Electrocatalytic Data for PtCo/C and PtNi/C Catalysts. EGA Electrochemical Surface Area, MA ORR Mass Activity, and SA ORR...

---