Highly Dispersed Pt₃Co Nanocatalysts Embedded in Porous Hollow Carbon Spheres with Efficient Electrocatalytic O₂-Reduction and H₂-Evolution Activities

Abstract

Developing highly active and reliable Pt-based catalysts is a major challenge for the widespread commercialization of proton-exchange membrane fuel cells. Herein, we have designed Pt3Co@C hollow sphere catalysts by the template method, in which PtCo alloy nanoparticles of approximately 3 nm diameter are anchored in a porous shell of nitrogen-doped carbon hollow spheres. Due to the confinement effect of the porous carbon shell, PtCo alloy nanoparticles possess excellent resistance to sintering, maintaining 2–3 nm size after calcination at 800 °C. Also, Pt3Co@C hollow sphere catalysts exhibit superior catalytic activity and stability in the oxygen reduction reaction, achieving 3.6 times the mass activity of the corresponding commercial Pt/C catalyst. Such catalysts with a mass activity retention rate of 87% after accelerated durability testing and no significant decay in activity after 10,000 potential cycles. Meanwhile, Pt3Co@C catalysts exhibit extremely high catalytic activity and surprising durability for the hydrogen evolution reaction process over the entire pH range. We believe that this methodology provides an insight into the preparation of high-performance electrocatalysts.

Pt3Co/C Catalyst on the Nitrogen-Doped Carbon Support with High Catalytic Activity and Stability

“…In order to test the electrochemical activity of the catalyst, RDE was selected to test the ORR performance, , and the performance of the Pt 3 Co/C-700 catalyst was compared with the commercial JM catalyst (JM 20%). The polarization curves for the ORR obtained with Pt/C, Pt 3 Co/C-600, Pt 3 Co/C-700, and Pt 3 Co/C-800 electrocatalysts in an O 2 -saturated 0.1 M KOH solution at 1600 rpm are shown in Figure a.…”

“…Electrochemical Performance. In order to test the electrochemical activity of the catalyst, RDE was selected to test the ORR performance, 28,41 and the performance of the Pt 3 Co/C-700 catalyst was compared with the commercial JM catalyst (JM 20%). The polarization curves for the ORR For a better understanding of the observed catalytic activities of the synthesized electrocatalysts for the ORR, the MA and specific activity (SA) at 0.9 V were calculated on the basis of the ORR polarization curves and the amount of Pt on the electrodes shown in Table S1.…”

“…Compared with the design of the carrier, the process of adding coating materials is simpler. Polydopamine (PDA), as a high molecular material containing only C, H, O and N, can limit the growth of the particles at high temperature by coating it on the outside of the NPs . It can also use the N left by the PDA decomposition to coordinate with Co, which can promote uniform dispersion and alloying.…”

“…Polydopamine (PDA), as a high molecular material containing only C, H, O and N, can limit the growth of the particles at high temperature by coating it on the outside of the NPs. 28 It can also use the N left by the PDA decomposition to coordinate with Co, which can promote uniform dispersion and alloying. This method is simple and feasible and provides a way for the commercialization of the Pt 3 Co/C catalyst.…”