PUB - Publikationen an der Universität Bielefeld

A commercial acid-leached bentonite (FULCAT (R)-22 F) catalyzed the dehydration of a range of alcohols efficiently under energy-saving conditions. Dehydration of a primary alcohol such as 1-hexanol took place in the 150-180 degrees C temperature range with a yield of 52%. This unexpected high catalytic activity was then studied by deeply characterizing the clay catalyst using both fundamental and advanced characterization methods. In agreement with VT-XRD results, by increasing the temperature, BET and PSD analysis evidenced a decrease in SSA (passing from 207 m2 g-1 at 180 degrees C to 175 m2 g-1 at 400 degrees C) and slight modification in the micropores present in the material (0.055 and 0.0039 cm3 g-1 at 180 degrees C and 400 degrees C, respectively). EDX showed that Fe, Mg, and K are the most abundant metals present in the structure. A deep spectroscopic analysis, with different basic molecular probes (CO, CD3CN, Py, and NH3), revealed, by increasing the temperature, a decrease in Br & oslash;nsted acid sites and an increase in Lewis acid sites. We hypothesized that the presence of these acidic sites is a key factor contributing to the observed high reaction yield of this clay-type catalyst.