Understanding the carbon morphology in sulfonated-silica ceramic carbon electrodes for the PEM fuel cell device

Abstract

Using hydrogen and oxygen gas, the fuel cell is a device that converts chemical energy into electrical energy. Particularly, the proton exchange membrane fuel cell, has multiple components, all that are consistently being studied in order to further increase its practicality. One particular limitation of the fuel cell is the use of the precious metal Pt within the catalyst layer. Efforts in decreasing the amount of Pt has provided information on improved utilization of the catalytic metal. Another limitation can be attributed to the perfluorosulfonated ionomer Nafion®, that is commercially available and used as a binder within the catalyst layer. The high cost and poor durability of current fuel cell catalyst layers has been linked to the use of Nafion® and the amount of carbon in the catalyst. In this work, 40 wt% Pt/C catalyst is used to obtain total electrode loadings as low as 0.2 mgPt cm-2, with the hypothesis of increased energy density while reducing catalyst layer thickness. This catalyst is used in conjunction with a Nafion®-replacement ionomer that contains sulfonated silica, and provides comparable performance while increasing durability. This work also includes the substitution of the typical carbon support, Vulcan, with ordered mesoporous carbon. In order to grasp a better understanding of the catalyst as a whole, mesoporous carbon will be used in efforts of obtaining more uniform Pt dispersion and greater catalytic activity. With a successful synthetic route of the mesoporous carbon, further studies are required for enhanced Pt deposition techniques on the two-dimensional support.