Stories tagged catalyst

Nanotube catalyst: 10,000 X smaller than human hairs
Nanotube catalyst: 10,000 X smaller than human hairsCourtesy St Stev

Solving the carbon dioxide problem

Burning fuel releases carbon dioxide and water vapor. A breakthrough process can reverse this reaction. The carbon dioxide and water vapor can be joined into molecules of methane, ethane, or propane by using sunlight as an energy source. The secret to doing this efficiently requires a particular catalyst with a large surface area.

(A) team (at Pennsylvania State University) found it could enhance the catalytic abilities of titanium dioxide by forming it into nanotubes each around 135 nanometres wide and 40 microns long to increase surface area. Coating the nanotubes with catalytic copper and platinum particles also boosted their activity.

Learn more:
Sun-powered device converts CO2 into fuel New Scientist

Aug
01
2008

Splitting water to store electricity: A snapshot showing the new, efficient oxygen catalyst in action in Dan Nocera's laboratory at MIT.
Splitting water to store electricity: A snapshot showing the new, efficient oxygen catalyst in action in Dan Nocera's laboratory at MIT.Courtesy MIT/NSF

Saving up energy for use at night

Want to be energy independent? Solar and wind energy are great but what do you do when the sun goes down and the wind doesn't blow? Batteries with the needed capacity are very expensive.

Energy can be saved up by breaking water apart into hydrogen and oxygen

Using a surprisingly simple, inexpensive technique, chemists have found a way to pull pure oxygen from water using relatively small amounts of electricity, common chemicals and a room-temperature glass of water. At night that oxygen can be combined with hydrogen (also extracted from water) in a fuel cell to make electricity.
The new process, enabling water to more easily be split, is to use a catalyst consisting of cobalt metal, phosphate and an electrode, placed in water.

"When electricity -- whether from a photovoltaic cell, a wind turbine or any other source -- runs through the electrode, the cobalt and phosphate form a thin film on the electrode, and oxygen gas is produced."
"The new catalyst works at room temperature, in neutral pH water, and it's easy to set up. That's why I know this is going to work. It's so easy to implement," Danial Nocera (MIT news office)

Within ten years

Nocera hopes that within 10 years, homeowners will be able to power their homes in daylight through photovoltaic cells, while using excess solar energy to produce hydrogen and oxygen to power their own household fuel cell. Electric vehicles will also power up from this home system.

Learn more: MIT News

Jun
29
2008

Nano structure self assembly
Nano structure self assemblyCourtesy Scott Warren and Uli Wiesner, Cornell University

Materials scientists perfect nano assembly of catalytic meshes

Catalysts, because of its shape, can speed up chemical reactions. Platinum is a useful catalyst in fuel cells but because it costs over $2000 an ounce, it needs to be used efficiently. One way to maximize the effectiveness of platinum is to maximize its surface area.

Cornell researchers have developed a method to self-assemble metals into complex configurations with structural details about 100 times smaller than a bacterial cell by guiding metal particles into the desired form using soft polymers. NSF News

How to self-assemble porous nano mesh

To keep nano spheres of platinum from clumping or "globbing" they are coated with an organic material known as a ligand. The innovative use of the ligands allows for the metal nanoparticles to be dissolved in a solution containing long co-polymer chains, or blocks, of molecules linked together to form a predictable pattern. After the spheres have filled in the spaces created by the co-polymer chains, heat is applied until the polymer turns to a carbon scaffold. The scaffold holds the platinum spheres in place until cooled. The carbon is then dissolved away leaving an intricate hexagonal mesh of platinum (see image above).

New surface textures will benefit plasmonics science

These metalic surfaces will also be of interest to scientists working in an area called plasmonics. Plasmonics is the study of interactions among metal surfaces, light, and density waves of electrons, known as plasmons. Improved optics applications, like lasers, displays, and lenses and better transmission of information within microchips will be some benefits.