Putting Platinum Catalysts on the Electrodes

Yet in view of the prospects of future mass production and massive applications of fuel cells in new areas, such as the electric car and portable electronic devices, further reduction of the platinum content to below 0.1 mg/cm, along with new technologies for the manufacture of electrodes with platinum catalyst more amenable to mass production, were needed. 

In this context, an efficiency criterion, often used in recent years for the utilization of platinum in electrodes, is formulated as it is the power of a fuel cell with electrodes using 1 mg of platinum catalyst and given in W/mg. 

This parameter is related to fuel cell production cost, while the parameter P2 (in mW/cm ) is related to the size (total surface area of the electrodes) that is needed for a fuel cell of given output. 

As a way of depositing thin layers of metals onto substrates, sputter deposition (SD) is a technology used widely in the semiconductor industry. Its advantages are simplicity, relatively low cost, the possibiUty of precise control of the amount of metal deposited and of layer thickness, and the feasibility of using a variety of metal targets (sources) and substrates. 

A number of workers noticed insufficient adhesion of the deposit to the substrate and insufficient long-term stability under operating conditions as defects of SD. It was pointed out, on the other hand, that the method, unlike in its applications in the semiconductor industry, is not required to yield continuous films when used to produce catalytic deposits deposition in the form of individual, catalytically active surface segments will be sufficient. 

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