PtCu₃, PtCu and Pt₃Cu Alloy Nanoparticle Electrocatalysts for Oxygen Reduction Reaction in Alkaline and Acidic Media

Abstract

Dealloying of Pt bimetallic nanoparticles is a promising synthesis method to prepare highly active electrocatalysts for oxygen reduction reaction (ORR) in alkaline and acidic PEM fuel cells. We present here a structural, compositional and electrochemical characterization linked with ORR activity for carbon supported PtCu 3 , PtCu, and Pt 3 Cu alloy nanoparticles in different electrolytes and pH values. The effects of electrolyte and pH are systematically examined on the ECSA and Pt mass based activity (j mass ) for various Pt-Cu alloys. We observed the formation of Cu oxide species and redissolution/redeposition of Cu species during the voltage cycling up to 1.0 V/RHE in 0.1 M KOH. In contrast, the voltage cycling in 0.1 M HClO 4 immediately causes the dissolution of Cu and results in Pt-enriched particle surface. We have correlated the ECSA and mass activity with the as-synthesized composition in dependence on both electrolytes. In summary, after voltage cycling in 0.1 M HClO 4 the values of j mass increase according: Pt 3 Cu < PtCu < PtCu 3 . However, after voltage cycling in 0.1 M KOH the values of j mass increase in the following trend: PtCu 3 < PtCu < Pt 3 Cu. Only after activation process, PtCu 3 core-shell catalyst shows significantly enhanced ORR activity in 0.1 M KOH compared to pure Pt.

Влияние термообработки на атомную структуру core-shell наночастиц PtCu в составе электрокатализаторов PtCu/C

“…Отметим, что после термической обработки при 350 • C на рентгенограмме появляются дополнитель-ные отражения при значениях 2θ ∼ 20.7, 53.2, 73.4 • , которые не связаны с оксидами или гидроксидами меди. Одним из возможных объяснений появления этих мак-симумов является формирование сверхструктуры, т. е. образование наночастиц со структурой интерметаллида состава PtCu в процессе нагрева и последующего мед-ленного охлаждения [7,16]. Отметим, что формирование упорядоченной структуры интерметаллида, по мнению ряда авторов, может приводить к повышению каталити-ческой активности [7].…”

Electrochemical Dealloying of PtCu/CNT Electrocatalysts Synthesized by NaBH4-Assisted Polyol-Reduction: Influence of Preparation Parameters on Oxygen Reduction Activity

“…Differences in the diffusion-limited current densities could be attributed to the unequal electrode coverage with catalyst [27]. The onset and half wave (E 1/2 ) potentials of the ORR polarization curve are often used to compare the electrocatalytic activity of different electrocatalysts.…”

Influence of the preparation method on Pt3Cu/C electrocatalysts for the oxygen reduction reaction

“…On the other hand, particular consideration and extensive attention of researchers have been given to PEMFCs due to their environmental friendly characteristics, high power density and low operation temperature [1][2][3][4][5][6][7][8][9][10][11][12][13]. Currently carbon supported Pt nanoparticles are extensively used as electrocatalysts in PEMFCs.…”

“…In particular, Pt-Cu alloy nanoparticles are catalyzing the attention as cathodic electrocatalysts in PEMFC due to significant improving of the ORR activity [1][2][3][4][5][6][7][8][9]20]. Liu et al [6] developed metallic PtCu multi-nanorods and reported an enhanced electrocatalytic activity and stability for ORR compared to conventional Pt/C catalysts.…”

“…Liu et al [6] developed metallic PtCu multi-nanorods and reported an enhanced electrocatalytic activity and stability for ORR compared to conventional Pt/C catalysts. Oezaslan et al [7] demonstrated that PtCu 3 , PtCu and Pt 3 Cu alloy nanoparticles over high specific surface area carbon can improve ORR activity compared to commercial Pt catalyst and reported an increased mass activity in acidic media (j mass : Pt 3 Cu < PtCu < PtCu 3 ). Mani et al [8], Cochell and Manthiram [5], and Hyun et al [2] synthesized and dealloyed the PtCu core-shell structure catalyst and observed the improving in ORR activity compared to commercial Pt/C.…”