Mesopore-functional carbon sphere nanochains and their integration with alloy nanoparticles for enhanced electrochemical performances

Abstract

One of novel porous 1-D architectures, mesopore-functional carbon sphere nanochains (MCSNs), with highly interrelated networks have been directly evolved from the colloidal carbon sphere nanochains (CCSNs) through a unique Li2CO3-molten salt strategy. The PtRu/MCSNs hybrid system, achieved by rational integration of 2.5-nm-size PtRu alloy NPs into the mesopores of MCSNs were prepared, and for comparison, the solid carbon sphere nanochain (SCSN)-supported PtRu NPs (PtRu/SCSN) and benchmark carbon (Vulcan XC-72)-supported PtRu (PtRu/C) were also prepared. It is demonstrated that the PtRu/MCSN hybrid system exhibited superior catalytic properties toward methanol oxidation with specially enhanced catalytic activity and desirable stability. The forward peak current density of PtRu/MCSNs (437mAmg−1) was obviously much higher than those of PtRu/SCSNs (265mAmg−1) and PtRu/C (310mAmg−1). The onset potential of PtRu/MCSNs (0.24V) is much earlier than those of PtRu/SCSNs (0.38V) and PtRu/C (0.37V). This attractive efficiency can be ascribed to the functionalities of mesoporous carbon support, which affords more efficient electron transfer and better mass transport, maximizing the availability of nano PtRu catalysts.