Titanium nitride materials with specific surface areas up to 200m ²g^-1 are tested in hydrogen transfer reactions. The TiN nanoparticles are obtained using pyrolysis reactions of donor-stabilized titanium halide precursors in ammonia atmosphere at high temperatures (973-1273K). The particles catalyze the reduction of alkynes to alkenes with complex hydrides such as NaAlH₄ in solution. Titanium nitride nanoparticles significantly accelerate the reduction of diphenylethyne (DPE) to stilbene. A high selectivity for Z-stilbene is observed for the TiN-catalyzed reaction whereas in the uncatalyzed reaction E-stilbene is the predominant product. The reduction of DPE to E:Z-stilbene is used as a test reaction to study the catalytic properties of the materials with respect to the specific surface area of the nanoparticles. The highest activity and selectivity is observed for catalysts synthesized at 973K. Filtration tests and recycling of the catalysts indicate that the reaction mechanism is heterogeneous and not homogeneous. NMR spectra of the intermediates formed in the course of the reduction are consistent with the presence of hydroalumination intermediates.