Elementary reaction steps and barriers for thiophene hydrodesulfurization (HDS) on a Ti8C12 nanoparticle were investigated using density functional theory. It is found that despite its high carbon concentration Ti8C12 displays a superior catalytic potential for hydrodesulfurization. Compared to the industrial catalysts, the hydrogen dissociation and C-S bond cleavage on Ti8C12 are more facile, and the removal of sulfur is energetically comparable. Our results also show that the catalytic activity of Ti8C12 can be associated with its unique structure that is quite different from that of bulk metal carbides.