Highly active carbon-supported Pt nanoparticles modified and dealloyed with Co for the oxygen reduction reaction

Carbon-supported ultrafine Pt nanoparticles modified with trace amounts of cobalt as enhanced oxygen reduction reaction catalysts for proton exchange membrane fuel cells

“…The broad peak located at 25° is assigned to the C(002) plane of the XC-72 carbon support, and the other four diffraction peaks at around 39.6°, 46.3°, 67.4°, and 81.4° correspond to the Pt (111), Pt (200), Pt (220), and Pt (311) planes, respectively, consistent with the fcc Pt lattice [24]. As is well known, the Pt-Pt interatomic distance is larger than the Co-Co one; hence, the incorporation of Co into the Pt lattice would lead to compressive strain and a shorter Pt-Pt distance, which will be retained after the leaching of excess Co from the intermetallic [25]. As shown in the XRD pattern, the peak positions of the Pt lattice of the Pt-Co/C catalysts are shifted to higher angles relative to those of Pt/C, due to the shorter Pt-Pt distance; moreover, the shifts increase with increasing initial Co contents in the Pt-Co catalysts, demonstrating that the smaller Co atoms are effectively doped into the fcc crystal structure of Pt to produce an alloy phase [26,27].…”

Gram-Scale Synthesis of CoO/C as Base for PtCo/C High-Performance Catalysts for the Oxygen Reduction Reaction

“…However, the material considered by them contains larger particles and a significant amount of spherical agglomerates. Similar morphological features of PtCo/C catalysts are characteristic of a large number of studies [21,23,25,31,55]. The results of elemental mapping of the PCC1 and PCC2 materials surface fragments indicate the preferential localization of platinum and cobalt atoms in the same places (nanoparticles) (Figure 4), which also confirms the preferential formation of bimetallic nanoparticles as a result of synthesis.…”

“…However, the material considered by them contains larger particles and a significant amount of spherical agglomerates. Similar morphological features of PtCo/C catalysts are characteristic of a large number of studies [21,23,25,31,55].…”

“…Note that the absolute mass activity values of the PtCo/C catalysts obtained in the present work are greater than those measured for the PtCo/C catalysts in [66,67]. Comparing our results with the literature data [25,55,68], we can conclude that the obtained PtCo/C catalysts are quite high in activity, their specific and mass activity of which significantly exceeds the activity of commercial Pt/C analogs. Stress testing of the catalysts leads to a decrease in their characteristics: the ESA value decreases, the half-wave potential shifts to the region of less positive values, and the activity in the ORR decreases (Figure 9a-f, Table 4).…”

Pt-CoOx nanoparticles supported on ETS-10 for preferential oxidation of CO reaction

“…The value obtained for the Pt crystallite was 2.2nm which is similar to the measured values by TEM for the nanoparticles, see Figure 1. The difference with TEM results could be because XRD reflects the crystal grain size rather than the actual particle morphology [31]. Beside the mentioned signals, peaks related to NaCl can be observed, these crystals would be formed from the synthesis salts since chlorides are use as metal precursors and the reduction agent is a sodium salt.…”