Ethanol contains an alcohol group (-OH), which includes hydrogen bonding. Hydrogen bonding is stronger than other IMFs such as Van der Waals forces and Dipole-Dipole.
Ethene only has Van der Waals forces as it is an alkene with only C-H or C-C bonds. These means that the forces are not as strong.
Since ethanol contains hydrogen bonding, it will take a higher temperature in order to break these bonds, and thus results in a higher boiling point than ethene.
