Hybrid catalysts developed for the thermo-catalytic cracking of liquid hydrocarbons were found to be capable of cracking C-4 (+) olefins into light olefins with very high combined yields of product ethylene and propylene (more than 60 wt%) and C-2-C-4 olefins (more than 80 wt%) at 610-640 A degrees C, and also with a propylene/ethylene weight ratio being much higher than 2.4. The olefins tested were heavier than butenes such as 1-hexene, C-10 (+) linear alpha-olefins (LAO) or a mixture of LAO. The hydrogen spillover effect promoted by the Ni bearing co-catalyst, contributed to significantly enhancing the product yield of light olefins and the on-stream stability of the hybrid catalyst.