Preparation and Characterization of Pt/buckypaper Catalytic Layer Based on Pt/CNTs Catalyst for Fuel Cells

Abstract

In order to increase the utilization of the precious metal catalysts in proton exchange membrane fuel cells, a new type of Pt/buckypaper catalytic layer with gradient structure was designed and prepared. Carbon nanotubes (CNTs) pretreated using ultrasonic method in mixed acid were used as the support of Pt catalyst. The Pt/buckypaper catalytic layer with Pt/CNTs gradient distribution was fabricated by simple filtration method. Several techniques such as scanning electron microscope, energy-dispersive X-ray spectroscope were utilized to characterize the microstructure and morphology of the catalyst and catalytic layer as well as the Pt distribution. The electrocatalytic performance of the catalyst and catalytic layer were measured by cyclic voltammetry and linear sweep voltammetry methods. The results show that the Pt particles were well dispersed on the CNTs support and the Pt particle size of Pt/CNTs was about 2.4nm. The electrochemical specific area (ECSA) of Pt/CNTs is similar to that of commercial Pt/C catalyst, while its specific mass activity and electrochemical stability were much higher than those of Pt/C. The ECSA of Pt/buckypaper catalytic layer can basically maintain the value of Pt/CNTs, indicating a high utilization of Pt. The novel gradient structure of catalytic layer manifests its promising applications in fuel cells.

Keywords

• proton exchange membrane fuel cell
• Pt catalyst
• carbon nanotube
• buckypaper
• gradient structure
• preparation