Friday, March 12, 2010

the secrets of the catalyst.

Microscope reveal the secrets of the catalyst.

A promising technique to observe the catalyst work can provide new knowledge about how the catalyst, this catalyst works, the scientists reported in the Netherlands.

This research team used X-ray microscope to examine the Fischer-Tropsch reaction in the catalytic reaction in a room specially made, and they also said this technology should be able to give scientists a greater understanding of the catalytic activity, allowing the design of catalysts, catalyst better.

Solid catalysts are widely used in chemical industry, and accelerate the production of many important compounds. These catalysts are usually composed of metal nano-meter size or particles of metal oxide, which is attached to a solid support with high surface area.

However, the catalyst, catalyst and structural changes of complex chemical reactions during the - so observe directly the reaction catalyst can provide useful clues to improve efficiency. But do this at the temperatures and pressures commonly used in the industry so far proved quite difficult.

Now, a team led by Frank de Groot, and Bert Weckhuysen at the University of Utrecht in the Netherlands, in collaboration with Lawrence Berkeley National Laboratory, U.S., has achieved this by using a small reaction space. This study is the first study to examine the heterogeneous catalysts at work in nano-scale, the team said.

Contour maps showing the composition of the catalyst (left) and the areas where most of the hydrocarbons produced (right)

In "nanoreaktor" De Groot, a reaction occurs between the two windows are sketched with a thickness of only 10nm. This design allows the X-rays through the reaction and on the detector, resulting in snap ongoing reaction. Some X-rays are absorbed by the catalyst, reactants and products - an absolute energy is absorbed shows their chemical compositions. The team is able to investigate the surfaces of the catalyst to a resolution of about 40 nm.

"This gives us an opportunity to examine the chemical changes that occur in a catalyst while reacting, said de Groot Chemistry World, which shows that the resolution is high enough to consider each of the catalyst particle." This means that can provide much useful information to us in the nano-scale. "

One of the studied reactions of this team is Fischer-Tropsch process - in which a solid catalyst of particles of iron oxide embedded in silica is used to convert carbon monoxide and hydrogen into liquid hydrocarbons that can be used as fuel.

Tim de Groot and Weckhuysen replicate these reactions in nano-reactors and found that they were during the reaction, iron oxide having a transformation. Early iron oxide (Fe2O3) is converted to another oxide (Fe3O4), before the iron silicate (Fe2SiO4) and metallic iron begins to form. Finally, iron carbide (FexCy) began to appear. Correlate with the catalyst composition in different areas with organic products are formed, this team showed that carbon accumulates in iron-rich area, with hydrocarbon products apart from the metal to the silicon support.

"These findings show great potential for heterogeneous catalysts, catalyst for the in situ dicitra," explained Alexis Bell at the University of California, Berkeley, United States. "I imagine that this process is not limited to observation of the catalyst particles, but can also be used in a variety of other applications, such as the detection levels of particulates from the air is responsible for the formation of acid rain."

Other uses include the monitoring of the proposed structural changes in materials or research of hydrogen storage distribution of medical nanoparticles in cells. It says the development team in the field of optics and imaging methods will improve the resolution of this technique.

Microscope reveal the secrets of the catalyst.

A promising technique to observe the catalyst work can provide new knowledge about how the catalyst, this catalyst works, the scientists reported in the Netherlands.

This research team used X-ray microscope to examine the Fischer-Tropsch reaction in the catalytic reaction in a room specially made, and they also said this technology should be able to give scientists a greater understanding of the catalytic activity, allowing the design of catalysts, catalyst better.

Solid catalysts are widely used in chemical industry, and accelerate the production of many important compounds. These catalysts are usually composed of metal nano-meter size or particles of metal oxide, which is attached to a solid support with high surface area.

However, the catalyst, catalyst and structural changes of complex chemical reactions during the - so observe directly the reaction catalyst can provide useful clues to improve efficiency. But do this at the temperatures and pressures commonly used in the industry so far proved quite difficult.

Now, a team led by Frank de Groot, and Bert Weckhuysen at the University of Utrecht in the Netherlands, in collaboration with Lawrence Berkeley National Laboratory, U.S., has achieved this by using a small reaction space. This study is the first study to examine the heterogeneous catalysts at work in nano-scale, the team said.

Contour maps showing the composition of the catalyst (left) and the areas where most of the hydrocarbons produced (right)

In "nanoreaktor" De Groot, a reaction occurs between the two windows are sketched with a thickness of only 10nm. This design allows the X-rays through the reaction and on the detector, resulting in snap ongoing reaction. Some X-rays are absorbed by the catalyst, reactants and products - an absolute energy is absorbed shows their chemical compositions. The team is able to investigate the surfaces of the catalyst to a resolution of about 40 nm.

"This gives us an opportunity to examine the chemical changes that occur in a catalyst while reacting, said de Groot Chemistry World, which shows that the resolution is high enough to consider each of the catalyst particle." This means that can provide much useful information to us in the nano-scale. "

One of the studied reactions of this team is Fischer-Tropsch process - in which a solid catalyst of particles of iron oxide embedded in silica is used to convert carbon monoxide and hydrogen into liquid hydrocarbons that can be used as fuel.

Tim de Groot and Weckhuysen replicate these reactions in nano-reactors and found that they were during the reaction, iron oxide having a transformation. Early iron oxide (Fe2O3) is converted to another oxide (Fe3O4), before the iron silicate (Fe2SiO4) and metallic iron begins to form. Finally, iron carbide (FexCy) began to appear. Correlate with the catalyst composition in different areas with organic products are formed, this team showed that carbon accumulates in iron-rich area, with hydrocarbon products apart from the metal to the silicon support.

"These findings show great potential for heterogeneous catalysts, catalyst for the in situ dicitra," explained Alexis Bell at the University of California, Berkeley, United States. "I imagine that this process is not limited to observation of the catalyst particles, but can also be used in a variety of other applications, such as the detection levels of particulates from the air is responsible for the formation of acid rain."

Other uses include the monitoring of the proposed structural changes in materials or research of hydrogen storage distribution of medical nanoparticles in cells. It says the development team in the field of optics and imaging methods will improve the resolution of this technique.

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