N-doped and un-doped graphene samples were synthesized starting from natural graphite of different particle sizes (10, 100 and 200 mesh) by oxidation and further thermal treatment under ammonia and inert atmospheres, respectively. Samples were thoroughly characterized by TEM, XRD, Raman and XPS. The nature and quantity of nitrogen species introduced were dependent on starting materials, reduction atmosphere (NH3. or inert) and temperature. All samples were employed as basic catalysts in the dehydrogenation reaction of ethanol. Acetaldehyde was the main product obtained owing to the basicity induced by the presence of N atoms in the graphene layers. Conversion increased with higher N at.% and lower number of stacked graphene sheets. Catalysts with highest ratio between both factors gave highest conversion values.