The Q-switched Nd:YAG laser is focused on a palladium target in the control chamber filled with various hydrocarbon atmospheres (C1-C4) to investigate their effect on the palladium ablated mass, gas reaction products, and corresponding plasma parameters (such as electron density Ne and plasma temperature Te) during molecular decomposition. The plasma parameters arise mainly from the Pd nanocatalytic activity during the laser-induced plasma process. We compare synthetic air atmosphere to hydrocarbon media to understand how the latter generates excess heat via oxygen-free exothermic (recombination) reactions. Subsequently, this gives rise to more energetic plasma and higher temperature, regarding the large amount of nanoparticles released into the plasma. The dynamics of the decomposition/recombination events accompany the nanocatalyst activity, leading to soot deposition all over the chamber.