祝贺2017级博士生颜婷婷的论文, “Cascade Conversion of Acetic Acid to Isobutene over Yttrium-Modified Siliceous Beta Zeolites”, 被ACS Catal发表。
The one-pot conversion of acetic acid to isobutene is a promising route for isobutene production, however, the attainment of high butadiene yield in this cascade reaction is challenging. Here, Y clusters confined in siliceous Beta zeolite were constructed and applied as robust catalysts for the acetic acid to isobutene conversion with a state-of-the-art isobutene yield of 60%, which corresponds to 90% of the theoretical maximum. The reaction network and mechanism were investigated by means of several complementary methods, namely temperature-programmed surface reaction (TPSR), in situ ultraviolet–visible spectroscopy (UV–vis) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The independent roles of weak acidic silanol groups and Lewis acidic Y species in each reaction step were elucidated. During the acetic acid conversion process, the weak acidic silanol groups and the confined Y species are both efficient in catalyzing the acetic acid ketonization and mesityl oxide hydrolysis, while the Lewis acidic Y species are highly active in catalyzing the acetone aldol condensation and mesityl oxide hydrolysis. With the synergistic effect between silanols and Y species as well as the zeolite structural confinement effects, a greatly enhanced isobutene production from acetic acid conversion could be achieved.