A New Type of Platinum Catalyst

A New Type of Platinum Catalyst

A platinum catalyst is a precious metal that makes it possible to conduct certain chemical reactions faster and more efficiently than they would otherwise be. It is a key ingredient in everything from fuel cells to automotive emission control systems. The catalyst allows the reaction to happen at a molecular level, rather than at a much larger scale where energy is needed to overcome friction and other obstacles.

The underlying principle has to do with the way the platinum atoms bond with hydrogen molecules on the surface. When the molecule of hydrogen adsorbs, or sticks, to the surface of the platinum, it weakens the H-H bond and splits into two oxygen atoms. When this happens, the oxygen atoms can then easily lose one of their electrons to platinum. This is how the platinum catalyst converts poisonous CO to non-toxic CO*2*.

Other types of chemical reactions can also take place on the platinum catalyst. For example, it can be used to convert a-ketoesters into chiral compounds via an asymmetric hydrogenation reaction. Other industrially important reactions that can be catalyzed with platinum include the metathesis reaction and the hydrosilylation reaction (where an organic Si-H bond is added to unsaturated multiple bonds to form organosilicon compounds).

What makes a platinum catalyst so effective is its ability to react with a wide variety of ligands. This flexibility is key to its success in fuel cells and other electrochemical applications. The catalyst is also very durable and can be reused.

A new type of supported platinum catalyst has been developed that enables reactions to occur more rapidly and under milder conditions than conventional catalysts. The catalyst is made from a combination of platinum and gallium. It is particularly good for the oxidation of carbon monoxide to carbon dioxide, which is an essential step in the production of clean-burning synthetic natural gas.

This research, funded by the Department of Energy Office of Science Basic Energy Sciences program, builds on previous work on solid-supported platinum. Using gallium instead of platinum, the team was able to design a catalyst that is three orders of magnitude more active than existing solid-platinum catalysts for this reaction. This is because the gallium has a more positive charge than platinum, which allows it to be closer to the negative charge of the oxygen molecule when it binds to the catalytic platinum atoms.

This closeness in orbitals helps to amplify the reaction, making it more effective and efficient. It also allows the platinum atoms to remain small and tightly packed together on the support, so that more of the surface area is available for the reaction. Typically, when platinum atoms are on a carbon support they grow in size as the load increases, which reduces the amount of surface area for the reaction to take place. The new platinum catalyst is able to resist this trend and maintains a high active platinum surface area even at higher loadings. This is a remarkable result that will open the door to new methods of producing clean, renewable fuels from fossil and renewable resources.