The most common and effective method of producing the acetic aldehyde is the oxidation of ethylene. The reaction proceeds thus:
2С2Н4 + O2 = 2СН3СОН
The synthesis is the use of a catalyst is palladium chloride. Moreover, if a direct oxidation of ethylene with oxygen, it is slow. Therefore, in the reaction mass is added salt of divalent copper to oxidized palladium, turning herself into monovalent copper, then oxidized with oxygen. That is, the copper in this synthesis serves as a carrier of oxygen. This reaction is called "Wacker process".
Acetaldehyde can also be obtained by hydration of acetylene. This synthesis, taking place in the presence of salts of mercury, called "reaction Kucherov". He proceeds as follows:
C2H2 + H2O = СН3СОН
In the laboratory, acetaldehyde can also be obtained using as raw materials ethyl alcohol, is the method that many consider almost a sacrilege. The reaction proceeds thus:
C2H5OH = СН3СОН + H2
That is, to obtain ethanal, is the dehydrogenation of ethanol at a high temperature using catalysts (copper or silver).
You can not "split off the hydrogen from ethanol, and subjected to oxidation, also at high temperatures and catalysts. Then the reaction will go as follows:
2С2Н5ОН + O2 = 2СН3СОН + 2Н2О