Effects of the Acidic and Textural Properties of Y-Type Zeolites on the Synthesis of Pyridine and 3-Picoline from Acrolein and Ammonia

A set of Y-type zeolites with Si/Al atomic ratios between 7–45 were studied as catalysts in the aminocyclization reaction acrolein and ammonia to produce pyridine 3-picoline. The catalytic activity tests at 360 °C revealed that conversion increased order Z45 < ZY34 ZY7 ZY17, agreement increase total acidity per gram catalyst. In all cases, bases cracking products (acetaldehyde formaldehyde) detected outflow from reactor. yield pyridines was inversely proportional for catalysts, which presented large surface areas micro- mesoporosity. selectivity towards 3-picoline favored when using a Brønsted/Lewis acid sites ratio close 1. formation occurred more selectively over Lewis than Brønsted sites. deactivation showed time on stream depended textural properties zeolites, i.e., pore volume BET area, evidenced by rate constants characterization spent catalysts. physicochemical determined XRD, UV-vis, Raman spectroscopies, infrared spectroscopy adsorbed pyridine, N2 physisorption, SEM-EDXS. After reaction, characterized spectroscopy, TGA, SEM-EDXS, indicating uniform deposition polyaromatic species catalyst within porous system resulted loss activity.