One-step synthesis of a Pt-Co-SWCNT hybrid material from a Pt-Co-MCM-41 catalyst

In this paper, we present a direct one-step synthesis of Pt-Co-SWCNT from the catalytic CO disproportionation over Pt-Co-MCM-41 catalysts with different Pt loadings. The SWCNT produced by Pt-Co-MCM-41 shows higher yield than the SWCNT produced by Co-MCM-41 under the same reaction conditions, and also SWCNTs with diameter larger than 2 nm have been identified in the products. X-ray absorption and temperature programmed reduction studies indicate that Pt exists as metallic nanoparticles in the Pt-Co-MCM-41 catalysts, while Co is atomically dispersed and tetrahedrally coordinated in the MCM-41 framework as a Co2+ cation. Detailed structural study also suggested that in the Pt-Co-SWCNT hybrids produced by this method, the Pt-Co bimetallic nanoparticles consist of a Pt core and Co shell with no detectable alloy phase. This study provides a method for the direct synthesis of a Pt-M-CNT catalyst, where M is a non-precious metal.