Hydrogenation of carbon-carbon multiple bonds is one of the most important processes widely used in chemical synthesis. We have shown for the first time that graphite-like carbon nitrides are capable of activating hydrogen molecules in the absence of any metals and can be successfully used as solid catalyst for the selective hydrogenation of phenylacetylene to styrene. This article presents the results of the investigation of the catalytic activity of mesoporous carbon nitride in the reaction of partial hydrogenation of phenylacetylene in the range of temperature 150-250 degrees C in the gas phase and at atmospheric pressure. The kinetic regularities of the reaction have been studied. A probable mechanism and the kinetic model of the reaction are formulated on the basis of the observed trends in the dependence of the initial rate from the temperature, concentration of phenylacetylene and catalyst mass.