With the goal of improving our capabilities to model surrogate fuels, in particular in relation to PAH and soot formation, the pyrolysis of n-heptane is studied in a single-pulse shock tube over a broad range of temperatures (900-1700 K) at 20 bar nominal pressure and 4 ms residence time. Three different initial fuel mole fractions were considered, 100, 500, and 2000 ppm of n-heptane in argon. Fuel and intermediate species, including aromatics up to phenanthrene, are measured using gas chromatography and mass spectrometry. An ongoing detailed chemical kinetic model for PAH chemistry has been updated to successfully capture the fuel decomposition, the formation of small hydrocarbons, and the concentration of the main PAH products. Major reaction pathways to PAHs are discussed as well as the role of important intermediate species.