Catalysts made of two tungsten precursors (one of them containing phosphorus) impregnated on EMT zeolite were nitridated in flowing pure ammonia and passivated by O-2 (1 vol%) in an Ar stream leading to tungsten oxynitrides/EMT (W2N/EMT) and phosphotungsten oxynitrides/EMT (PW2N/EMT). The catalysts were examined by X-ray diffraction, NMR spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The materials were tested for the cracking/isomerization of n-heptane at atmospheric pressure and 623 K. Cracking (C-3 + C-4) was the major (about 90%) n-heptane reaction for all the catalysts. The influence of EMT supercages upon selectivity was observed. The yield of n-haptane isomers was significantly enhanced for W2N/EMT and principally for PW2N/EMT showing a higher hydrogenation function.