Fuel cell catalyst
Anode catalysts include platinum ruthenium, platinum tin, platinum WO3, platinum molybdenum, etc.
For fuel cells, the catalysts studied or used by various countries, laboratories and automobile manufacturers are generally different and confidential, which is the core technology. But the factors that may lead to poisoning are similar.
1, CO, which is generally a fuel cell with alcohol as fuel;
2. SO2 will be contained in many organic fuels, and most catalysts will be poisoned;
3, carbon deposition, C is easy to accumulate on the reaction interface, which hinders the reaction from continuing. The reaction temperature should not be too high, and temperature is often the killer of catalyst activity.
As for the service life, it is related to the formula of the catalyst.
Because the proton exchange membrane can only conduct protons, hydrogen ions (protons) can directly pass through the proton exchange membrane to reach the cathode, while electrons can only reach the cathode through the external circuit. When electrons flow to the cathode through an external circuit, direct current is generated.
Up to now, the most commonly used proton exchange membrane is Nafion proton exchange membrane of DuPont Company, which has the advantages of high proton conductivity and good chemical stability. Most PEMFC adopts perfluorosulfonic acid membranes such as Nafion, and the PEM used to assemble PEMFC in China mainly depends on imports. However, Nafion proton exchange membrane still has the following disadvantages: (1) it is difficult to make and its cost is high, the synthesis and sulfonation of perfluoro substances are very difficult, and the hydrolysis and sulfonation in the process of film formation are easy to denature and degrade the polymer, which makes the film formation difficult and leads to high cost; (2) It requires high temperature and water content, and the best working temperature of Nafion series membranes is 70 ~ 90℃. If it exceeds this temperature, the water content and conductivity of Nafion series membranes will decrease rapidly, which hinders the improvement of electrode reaction speed and overcomes catalyst poisoning by increasing the working temperature appropriately. (3) Some hydrocarbons, such as methanol, have high permeability and are not suitable for proton exchange membrane (DMFC) in direct methanol fuel cells.
The price of Nafion membrane is about $600 per square meter, which is equivalent to $0/20 per kilowatt/kloc (unit battery voltage is 0.65V). In the fuel cell system, the cost of membrane accounts for almost 20%~30% of the total cost. In order to realize the commercial application of fuel cells as soon as possible, it is urgent to reduce the price of proton exchange membrane. Ballard Company of Canada has done very well in the field of proton exchange membrane, which makes people see the hope of commercialization of exchange membrane. According to the research plan, its third generation proton exchange membrane BAM3G is a partially fluorinated sulfonic acid proton exchange membrane. Its demonstration life has exceeded 4500h, and the price has dropped to 50 US dollars per cubic meter, which is equivalent to 0/0 US dollars per kilowatt/kloc (the unit battery voltage is 0.65V).
The above information is for reference only, I hope it can help you.