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.