Influence of basicity on 1,3-butadiene formation from catalytic 2,3-butanediol dehydration over γ-alumina

Journal Article · Thu Dec 01 00:00:00 EST 2016 · Journal of Catalysis

DOI:https://doi.org/10.1016/j.jcat.2016.09.003· OSTI ID:1463645

Zeng, Fan ^[1]; Tenn, William J. ^[2]; Aki, Sudhir N. V. K. ^[2]; Xu, Jiayi ^[1]; Liu, Bin ^[1]; Hohn, Keith L. ^[1]

---

1. Kansas State University, Durland Hall, Manhattan, KS (United States). Department of Chemical Engineering
2. INVISTA S.à r.l., Orange, TX (United States). Intermediates R&D

The direct catalytic conversion of 2,3-butanediol (BDO) to 1,3-butadiene (BD) was studied over two commercial forms of alumina (denoted as F200 and SCFa) at temperatures between 240 C and 450 C. Even though these two catalysts are both high surface area forms of c-alumina, they gave remarkably different results, with SCFa giving higher BD selectivities at all experimental conditions. The difference is attributed to the higher surface area of F200, which means a greater number of acid sites that can convert BDO to methyl ethyl ketone (MEK). NH3 and CO2-TPD results supported this conclusion by showing that the two forms of alumina had different acid/base properties. Experimental results also showed that BD selectivity was improved by increasing temperature, increasing residence time and co-feeding water. The residence time study combined with density functional theory (DFT) calculations proved that 3-buten-2-ol (3B2OL) is an important intermediate in the conversion of BDO to BD. BD selectivity decreases over sodium modified alumina SCFa. It is hypothesized that on sodium-modified alumina, 3B2OL is dehydrogenated to form methyl vinyl ketone (MVK) as opposed to dehydration to BD. Basic sites catalyzed the retro-aldol condensation of MVK, which produces acetone and formaldehyde via cleavage of the C@C bond. This is in agreement with DFT calculations showing that the proposed pathway for acetone formation is more energetically favored on Na-modified c-Al2O3 (110) surface compared to the pristine (110) surface.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1463645
• Journal Information: Journal of Catalysis, Vol. 344, Issue C; ISSN 0021-9517
• Publisher: Elsevier
• Country of Publication: United States
• Language: English