Amorphous silica-alumina modified with silver as an efficient catalyst for vapor-phase dehydration of 1,3-butanediol to 1,3-butadiene.

Several silica-alumina modified with Ag were examined as catalysts in the dehydration of 1,3-butanediol to 1,3-butadiene (BD). Among several catalysts tested, an amorphous silica-alumina (SAL-3) modified with Ag operated in H 2 flow gave the highest improvement in catalytic activity and stability. The improvement of catalytic activity and stability of this Ag/SAL-3 was due to the generation of reversible acid sites. Several parameters, such as reaction temperature, contact time, Ag content, and carrier gas, influenced the catalytic activity of the Ag/SAL-3 catalyst. The highest BD yield of 82.5 % was attained at 225 °C, while the highest BD productivity of 1.33 g g cat -1 h-1 with a BD selectivity of 68.9 % was achieved at 250 °C. The role of the Brønsted and Lewis acid sites was revealed by poisoning experiments of co-feeding 2,6- or 3,5-dimethylpyridine with 1,3-butanediol. [Display omitted] • Efficient dehydration of 1,3-butanediol (1,3-BDO) to 1,3-butadiene (BD) proceeded over Ag-modified silica-alumina (Ag/SAL-3). • The presence of Ag and the operation in H 2 flow improved the activity and stability of SAL-3. • Ag/SAL-3 catalyst employed in H 2 gas generated reversible acid sites. • Both Brønsted and Lewis acid sites played essential roles in the dehydration of 1,3-BDO to BD. • The highest BD yield of 82.5 % was achieved at 225 °C over Ag/SAL-3 at a Ag content of 3 wt%. [ABSTRACT FROM AUTHOR]