Formation of Aldehyde when Primary Alcohol undergoes Catalytic Dehydrogenation

Primary alcohols have the formula R-CH2OH, which has a –OH group attached to a carbon atom that is also attached to one hydrogen atom and one alkyl group. When primary alcohols undergo catalytic dehydrogenation, they lose two hydrogen atoms from the carbon atom attached to the –OH group, and the –OH group is replaced by a double bond with one of the neighboring carbon atoms. This results in the formation of an aldehyde, which has the formula R-CHO.

The process of catalytic dehydrogenation involves the use of a catalyst, such as copper or nickel, and a source of hydrogen gas. The catalyst helps to break the bonds between the hydrogen atoms and the carbon atom, and the hydrogen gas provides the necessary hydrogen atoms to form new bonds with the carbon atoms.

The mechanism for the catalytic dehydrogenation of primary alcohols involves the following steps:

1. Adsorption of alcohol on the surface of the catalyst
2. Dehydrogenation of the alcohol to form an aldehyde intermediate
3. Desorption of the aldehyde intermediate from the catalyst surface

The aldehyde intermediate can be further oxidized to form a carboxylic acid or reduced to form a primary alcohol. However, under the conditions of catalytic dehydrogenation, the aldehyde intermediate is typically desorbed from the surface of the catalyst before it can be further oxidized or reduced.

In conclusion, when a primary alcohol undergoes catalytic dehydrogenation, it forms an aldehyde. This process involves the use of a catalyst, such as copper or nickel, and a source of hydrogen gas. The mechanism involves the adsorption of the alcohol on the surface of the catalyst, dehydrogenation of the alcohol to form an aldehyde intermediate, and desorption of the aldehyde intermediate from the catalyst surface.