Microporous and Micro-meso-macroporous Y Zeolites in the Synthesis of 2-Methyl-5-ethylpyridine

The study investigates the catalytic properties of microporous (H–Y) and micro-meso-macroporous (H–Y-mmm) FAU-type zeolites in the synthesis of 2-methyl-5-ethylpyridine (MEP) by the reaction of acetaldehyde with ammonia. At 150°C, an acetaldehyde to ammonia molar ratio of 1 : 3, and a catalyst content of 10 wt %, a MEP yield of 58% (0.95H–Y) and 63% (0.95H–Y-mmm) was achieved with a MEP selectivity of 91 and 93%, respectively. The examination of the catalyst stability revealed that hierarchical H–Y-mmm zeolites ensure a 100% MEP selectivity during 4–5 cycles with a slight decline in the catalytic activity, while H–Y zeolites are active during the first cycle only.