Preparation Of Pt/CMK-3 Anode Catalyst And Its Application In Direct Methanol Fuel Cell

As it has the advantage of environmental-friendliness, easy used liquid fuel,and relatively low requirement of operation condition, direct methanol fuel cell (DMFC) will be expected to be a new generation of power. The operation of DMFC involves methanol oxidation and oxygen reduction over precious metal catalysts dispersed on a carbon support with large surface area, such as carbon nanofibers, carbon nanotubes, carbon spheres and ordered mesoporous carbons (OMC),etc.Numerous research works have been focused on both catalyst dispersion and carbon-support design in order to enhance the catalytic activities.Ordered mesoporous carbons CMK-3 with various morphologies are synthesized by using various mesoporous silica SBA-15 as template and then support to prepare Pt/CMK-3 catalyst. The obtained catalysts are compared in terms of the electrocatalytic activity for methanol oxidation in sulfuric acidic solutions.The structure characterizations and electrochemical analysis reveal that Pt catalysts with the CMK-3 support of large particle size and long channel lengths possess larger electrochemical active surface area (ECSA) and higher activity toward methanol oxidation than those with the other two supports do. The better performance of Pt/CMK-3 catalyst may be due to the larger area of electrode/electrolyte interface and larger ECSA value of Pt catalyst,which will provide better structure in favor of the mass transport and the electron transport.Forthermore, the present work describes a new approach to directly electrodeposit platinum nanoparticles on the mesoporous carbon CMK-3 through cyclic potential scanning technique and to prepare a CMK-3 including platinum nanoparticles modified electrode (noted as Pt/CMK-3).TEM image shows that Pt nanoparticles are attached on the out surface of the CMK-3 with average particle size about 5 nm.The electrocatalytic activity of Pt/CMK-3 for methanol oxidation was studied.When the platinum loading was 20 wt% in the catalysts,the H2PtCl6 have a higher value in preparation.The obtained Pt/CMK-3 catalyst possessed higher electrocatalytic activity than Pt/XC-72 and Pt/CMK-3(â…¡) which prepared by ordinarily electrodeposited method.