They develop a method to manufacture less Platinum fuel cells

An international team of researchers, including scientists from the Higher Council of scientific research (CSIC), has been multiplied by 10 speed which takes place the reduction of oxygen on Platinum, an electrochemical reaction which depends on the electric power provided by fuel cells. The new method could allow manufacturing cathodes for these batteries with much less Platinum, which make them economically more competitive. The results of the work published in the latest issue of Nature Chemistry.

Fuel cells directly convert chemical energy contained in hydrogen into electrical energy, generating water as a single product. They are more or less powerful depends on the product of the voltage of the battery for the electric current that flows when the circuit is closed. This current is equivalent to the speed of two electrochemical reactions: the hydrogen oxidation and oxygen reduction. "One of the main constraints for the development of such technology is the low speed which is the reduction of oxygen, which means lower power for a same voltage." "In addition, you have to use large amounts of Platinum to get the desired power makes too much fuel cells", explains one of the authors of the work, the researcher at the CSIC Angel Cuesta.

The slope in the Institute of chemistry and physics Rocasolano group, in collaboration with scientists at the Argonne National Laboratory, Illinois (United States), has focused on manipulating the atoms present on the surface of the Platinum, a metal usually used as a catalyst for the stack being the most active in accelerate the necessary to generate chemical reaction electricity.

Schematic representation of process of breakdown of the link O in the oxygen molecule (O2) in the presence of sulfuric acid or phosphoric acid, on clean Platinum and Platinum modified with cyanide (B). Source: CSIC.

"We have tried to maintain the chemical properties of the surface atoms of the Platinum and we have changed the size and the geometrical structure of groups of Platinum atoms exposed to the internal environment of the battery or electrolyte", emphasizes Cuesta. During the experiments, the researchers managed to retain molecules of cyanide on the surface of a Platinum electrode with the objective of which would be two or three Platinum atoms necessary to make it break the O-O link in the oxygen molecule (O2) in line. "Thus, speed to which passes the reduction of oxygen is multiplied by 10 using acid phosphoric as electric driver and 25 in the case of sulfuric acid", adds the researcher at the CSIC.