A method is developed for creating highly active and selective catalysts for associated petroleum gas cracking which is based on use of activated carbons derived from renewable sources of plant raw materials (Jerusalem artichoke, false flax, rape, wheat) modified with nanosized iron particles obtained in reverse-micellar solutions. It is shown that carbon matrices modified with iron nanoparticles possess a high catalytic activity with the maximum conversion attained at 900 K and a high selectivity for olefin formation (about 95%).