Increase of Zr-β zeolites Lewis acidity and insights into the reactivity enhancement.

Zr-β zeolites were modified with second metals to catalyze the conversion of ethanol/acetaldehyde to 1,3-butadiene. The incorporation of Ta increases the Lewis acidity of Zr-β zeolite, resulting in higher catalytic activity than that of In, Y and Ce. Furthermore, the Zr-β zeolite that was first incorporated with Zr and then Ta with a Ta/Zr molar ratio of 1.5 exhibited greater catalytic activity of 57% conversion and 75% selectivity. Activity descriptors were proposed to calculate the reactivity of key reaction steps, which served as evidence that Ta incorporation enhances the aldol condensation and MPV reduction reaction activity, thus improving catalytic performance. [Display omitted] • The metals Zr and Ta were sequentially incorporated into the framework of β zeolite. • The second metal Ta was incorporated into the Zr-β zeolite to establish new Lewis acid sites. • The strengthening Lewis acidity is contributed to enhancing the activity of aldol condensation and MPV reduction. • A mathematical descriptor was defined to analyze the reactivity of aldol condensation and MPV reduction. [ABSTRACT FROM AUTHOR]