- The catalytic combustion unit is heated with a Bunsen burner until the bottom starts to glow red.
- The gas is then quickly shut off, the burner is inserted into the glass tubing, and the gas is turned on again.
Chemical Concepts Demonstrated: Heat-based catalysis, use of a ceramic as the solid support for a catalyst
Demonstation:
The catalytic combustion unit consists of a glass tube with a honeycomb block of
ceramic coated with a noble metal (platinum and/or palladium) inside.
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Observations:
The bottom continues to glow red hot.
Explanation:
The catalyst in this situation is the ceramic/metal block. It catalyses the oxidation of whatever fuel that the Bunsen burner happens to be running off of. The product from this oxidation is not flammable, and a match would go out if it were held above the unit.
Catalytic combustion units are used on such devices as automobiles and wood-burning stoves. When the fuel in these devices is combusted, there is a chance that the combustion will be incomplete. Combustion units such as these complete the oxidation of these fuels and, as a result, produce more heat and less pollutants.