Aug 24 2004
Oxford NanoScience Ltd has announced the availability of a new accessory for the 3DAP 3-Dimensional Atom Probe. A new reaction cell has been introduced to allow investigations of catalytic reactions between process gases and metal surfaces.
This is invaluable in both understanding the mechanisms of catalysis and providing scope for improvements in industrial catalysts. The system is ideally suited to simulate automobile engine exhaust environments to allow studies to be made of automotive catalytic converters.
Equipped with gas inlet and outlet ports and a heater, the catalytic reaction cell is mounted on 3DAP and is differentially pumped. This means that samples can be heated to temperatures up to 873K in the presence of a process gas such as NO, CO, SO2 or O2 before being transferred into 3DAP. The process gases may be introduced at flow rates of up to 1 L/hr.
Field Ion Microscopy and 3DAP are excellent techniques for fundamental investigations of catalytic reactions on metal surfaces since the shape of the sample tip exposes multiple crystallographic faces. This provides a good model for real catalyst particles. 3-DAP allows identification of both the chemical composition and atomic position of each species in successive layers through the sample surface.
Once specimens have been treated with the gases of interest at the appropriate temperature, 3DAP analyses reveal the exact sites of gas species adsorption on the atomic surfaces. Atom maps of the sample can be reconstructed, with each dot in the map representing a single atom from the specimen, colour coded to show its chemical identity.
For more information on microscopy, click here.
August 23rd, 2004