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

Abstract

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.