<p>C-H bond activation in light alkanes figures among the most important industrial processes in our days. Of particular interest is ethane dehydrogenation to generate ethylene, a chemical precursor for the preparation of a number of commercially interesting compounds. In the present work, we investigate the ethane dehydrogenation to ethylene catalyzed by Au, as represented by an Au₈ cluster. The double-hybrid DFT functional DSD-PBEP86 was used to obtain the intermediates and transition states for some competitive reaction paths. The two most important of these pathways were used to structure a set of kinetic rate equations from which the concentration of each intermediate throughout the reaction was obtained. The model equations allowed us to determine under which conditions each product, i.e. CH₄ or CH₂CH₂, is favored. Under high hydrogen availability, CH₄ is the main product. When the only source of hydrogen is the dehydrogenation of CH₃CH₃ itself, H atoms over Au should be rare and CH₂CH₂ is expected to be predominant. Finally, we used a combination of wave function analysis techniques in order to give a chemical interpretation for the relative activation energies in the main steps involved in each of the two competing routes.</p>