Controllable Unzipping of Carbon Nanotubes as Advanced Pt Catalyst Supports for Oxygen Reduction

Alternative carbon support materials provide great opportunities to fabricate advanced catalysts with enhanced activity and durability, especially for energy conversion and storage technologies based on the oxygen reduction reaction (ORR), such as fuel cells and metal–air batteries. In this work, a series of controllable unzipped carbon nanotubes (CNTs) have been successfully synthesized and used as Pt supports for highly efficient ORR catalysts. Benefiting from the unique structure constructed by the 1-D and 2-D nanomaterials, outstanding catalytic performance with enhanced Pt utilization, ORR activity, and durability is achieved for the catalyst of Pt loaded on the medium-level unzipped CNTs, with a remarkable half-wave potential of 0.915 V (vs RHE). The effective mass transport in the cathodes fabricated with the 3-D nanoarchitecture hybridized with CNTs and graphene ribbons catalyst supports results in a significant increase of peak power density for direct methanol fuel cells (DMFCs) compared to that of a traditional electrode with commercial Pt/C catalyst, which demonstrates a great application potential of this novel catalyst design.