If the reaction products are 10% coke 40% long chain HC's 10% med chain HC's and 40% short chain HC gasses before the use of a catalyst and they are 1% coke 1% long chain HC's 90% med chain HC's and 8% short chain HC's and gasses after the addition of the catalyst to the process. I'm sorry, but I do not believe that scenario is possible by introducing only a catalyst. Whoever told you that is lying IMO.