Which catalyst is used to convert ethanol to ethene in dehydration?

• A. Palladium on carbon
• B. Aluminium oxide
• C. Nickel
• D. Platinum

Answer: (B)

Dehydration of ethanol to ethene is an elimination process that needs an acid catalyst to remove water and form a double bond. A solid acid like aluminium oxide provides the acidic sites on its surface that protonate the alcohol and allow water to leave, producing ethene. The other catalysts listed are metals that are used for hydrogenation or dehydrogenation reactions, not the dehydration route to ethene, so they don’t promote this conversion as effectively. Therefore, aluminium oxide is the best fit for this reaction.