Cooperative Catalysis by Surface Lewis Acid/Silanol for Selective Fructose Etherification on Sn-SPP Zeolite

Journal Article · Mon Aug 20 00:00:00 EDT 2018 · ACS Catalysis

DOI:https://doi.org/10.1021/acscatal.8b01615· OSTI ID:1543702

Josephson, Tyler R.  ^[1]; DeJaco, Robert F. ^[2]; Pahari, Swagata ^[2]; Ren, Limin ^[2]; Guo, Qiang ^[2]; Tsapatsis, Michael  ^[2]; Siepmann, J. Ilja  ^[2]; Vlachos, Dionisios G.  ^[3]; Caratzoulas, Stavros  ^[3]

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1. Univ. of Delaware, Newark, DE (United States); Univ. of Minnesota, Minneapolis, MN (United States)
2. Univ. of Minnesota, Minneapolis, MN (United States)
3. Univ. of Delaware, Newark, DE (United States)

While Lewis-acid zeolites, such as Sn-Beta, catalyze glucose isomerization in an alcoholic medium, mesoporous Sn-SPP catalyzes both glucose isomerization to fructose and fructose etherification (formally ketalization) to ethyl fructoside, enabling fructose yields in excess of the glucose/fructose equilibrium. Using periodic density functional theory calculations and force-field-based Monte Carlo simulations, the ketalization reaction mechanism and adsorption behavior were examined. The silanols on the Sn-SPP mesopore surface facilitate the ketalization reaction through hydrogen bonding interactions at the transition state, only possible via a Sn–O–Si–OH moiety, present in Sn-SPP but not in Sn-Beta. Fructose ketalization is favored over glucose acetalization due to differences in stability of the oxonium intermediates, which are stabilized by the Sn-SPP active site. The open site of hydrophobic Sn-Beta cannot perform these reactions because its active site does not contain an adjacent silanol of the right geometry. Finally, in addition to the more favorable activation barrier of the catalytic process, the adsorption at the catalytic site in Sn-SPP is also found to be more favorable than for Sn-Beta, in spite of competitive adsorption between fructose and ethanol in the ethanol-saturated zeolites.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Catalysis Center for Energy Innovation (CCEI); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States); Univ. of Delaware, Newark, DE (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-05CH11231; SC0001004
• OSTI ID: 1543702
• Alternate ID(s): OSTI ID: 1662006
• Journal Information: ACS Catalysis, Vol. 8, Issue 10; ISSN 2155-5435
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
chemistry
biomass processing
sugars chemistry
ketalization
acetalization
Gibbs ensemble Monte Carlo
adsorption