can I put adhesive floor tiles over ceramic tiles in my kitchen

You would need to level the floor first with a latex self levelling screed for a smooth surface or the ridges and grout lines will wear through. Geof G&H

Would require screeding before laying the vinyl tiles, Easy enough job, Make sure you leave the screed to go off properly before laying the new vinyl tiles, Each screed has its own reccomendations so read the pack and follow the instructions. Wickes have a very good product, Latex self levelling screed, goes hard in about and hour or two and only need to leave it 24hours before applying new floor.