Tuning surface composition of multiwalled carbon nanotubes supported Pt-Co bimetallic nanoparticles for boosting methanol oxidation catalysis

Abstract

Developing catalysts with high performance and low cost for methanol oxidation reaction (MOR) is the key to promoting the industrialization of direct methanol fuel cells (DMFCs). In this work, multiwalled carbon nanotubes (MWCNTs) supported PtCo alloys catalysts with improved MOR properties and anti-CO poisoning ability are successfully prepared by integrating low temperature adsorption and high temperature reduction method. The Pt1Co3@NC/MWCNTs sample with moderate Co2+ feeding content (0.81 mA/ugPt) achieves a factor of 1.93 enhancement in MOR mass activity compared to the commercial Pt/C catalyst (0.42 mA/ugPt). In addition, the Pt1Co3@NC/MWCNTs sample displays a lower CO oxidation onset potential respect to pristine Pt/C catalyst (0.74 V vs. 0.82 V). Scuh improvement of MOR activity, durability and anti-CO poisoning ability of the Pt1Co3@NC/MWCNTs catalyst is ascribed to the moderate surface compositions, optimal electronic interaction between PtCo alloys and MWCNTs, and the protection of N-doped carbon (NC) shells. This study provides a new direction to decrease the utilization of platinum and improve the MOR activity, stability and anti-CO poisoning ability of electrocatalysts which will be potential in design and fabrication of the highly efficient electrocatalysts for DMFCs applications.