Direct Methanol Fuel Cell Catalyst
Fuel cells are the best means to combat energy crisis and air pollution. They are efficient, eco-friendly and used for power production. They produce electricity from an electromagnetic reaction between hydrogen and oxygen. There are different types of fuel cells based on the electrolyte used. Methanol is used as the electrolyte in Direct Methanol Fuel Cell. DMFCs can be used in small electronic devices like cell phones and palm-sized computers. But few specific problems have kept them out of general use. To curb these problems various types of Direct Methanol Fuel Cell Catalyst are used. They enhance the performance of DMFCs by reducing methanol oxidation in the cathode compartment of the fuel cell.
The two major problems plaguing the development of DMFCs are:
- Poisoning of the catalyst due to the chemical compounds formed during operation.
- Fuel crossing over from the anode to the cathode without producing electricity
DMFCs are electro chemical devices that convert high energy density fuel [liquid methanol] directly to electricity. Transportation and storage of hydrogen is a big problem. It can't be transported as easily as petrol. So the best way is to generate hydrogen on board in the vehicle from hydrocarbon fuels such as methanol and other alcohols. This process is called reforming. The reformate produced contains hydrogen, carbon di oxide and trace amounts of carbon monoxide [Co]. The problem is, Co acts as a poison to the platinum [pt] based anode catalyst and degrades the overall performance. Production of the Direct Methanol Fuel Cell catalysts that are resistant to Co became the prime factor of research. Currently carbon supported platinum-ruthenium [Pt Ru] alloys are used as catalysts.
Another problem is the methanol "cross over" issue. The solid polymer electrolyte used to separate the anode and cathode in the cell is permeable to methanol, which is the fuel. This allows methanol to pass over to the cathode. There it interferes with cathodic reaction that causes a loss of potency in electricity production and general degradation of the device. Many research groups tried to make the electrolyte impermeable to methanol. As an alternative Direct Methanol Fuel Cell Catalyst are developed.
The use of enzymes as Direct Methanol Fuel Cell Catalyst has come up to combat the menace of crossing over problem. They have many advantages over traditional noble-metal catalysts. Enzymes are highly selective i.e., they will only catalyze very specific reactions, depending on which enzyme is used. They are also easily available. If a fungus produces the enzyme, a large scale of fungi can be cultured. They are ready made to operate at biological temperature and PH, far milder than the conditions at which noble-metal catalysts are active.
Luke heart research group develops novel synthesis strategies for the preparation of metal alloy/carbon and nanocomposites as Direct Methanol Fuel Cell Catalyst that perform 50% greater than traditional Pt-Ru catalysts.