As the world’s accessible oil reserves dwindle, natural gas has become an increasing important energy source. The primary component of natural gas is methane, which has the advantage of releasing less carbon dioxide when it’s burned than do many other hydrocarbon fuels. But because of the very stable structure of the methane molecule, it can be difficult to access the energy stored within. When unburned methane escapes into the atmosphere, it’s a greenhouse gas 20 times more powerful than carbon dioxide.
Now, researchers have created a material that catalyzes the burning of methane 30 times better than do currently available catalysts.
The discovery offers a way to more completely exploit energy from methane, potentially reducing emissions of this powerful greenhouse gas from vehicles that run on natural gas. The catalyst may also offer a cleaner and cheaper way of generating energy from catalytic combustion in gas turbines.
Conventional catalysts for methane combustion are composed of metal nanoparticles, and in particular palladium (Pd), deposited on oxides such as cerium oxide (CeO2). Tweaking that approach, the researchers instead used a method that relies on self-assembly of nanoparticles. They first built the palladium particles — just 1.8 nanometers in diameter — and then surrounded them with a protective porous shell made of cerium oxide, creating a collection of spherical structures with metallic cores.
Because small particles such as these tend to clump together when heated and because these clumps can reduce a catalyst’s activity, the team deposited them on a hydrophobic surface composed of aluminum oxide to ensure they were evenly distributed.
Testing the material’s activity, the researchers found that their core-shell nanostructure performed 30 times better than the best methane combustion catalysts currently available, using the same amount of metal. It completely burned methane at 400 degrees C.
The researchers plan to further study the structure of the new catalyst to better understand why it works so well. And they will use similar methods to create new materials to test.
This story is reprinted from material from University of Pennsylvnnia, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.