TY - JOUR
T1 - Sulfonic Acid-Functionalized Zeolite Beta
T2 - Bronsted Acid Catalysts for Reactions Involving Liquid Water
AU - Lusardi, Marcella
AU - Davis, Mark E.
N1 - Funding Information:
This work was supported as part of the Catalysis Center for Energy Innovation (CCEI), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DE-SC0001004.
Publisher Copyright:
© 2021 American Chemical Society
PY - 2021/12/20
Y1 - 2021/12/20
N2 - The utility of zeolites in biomass upgrading reactions can be limited in cases where stronger Bronsted acidity and/or hydrophobicity are required for effective catalysis. While sulfonated solids/sulfonic acid catalysts can be used in such cases, they forego the advantageous effects of confinement that are afforded by zeolites. Here, acidity, hydrophobicity, and confinement are integrated into a solid material by functionalizing the intrapore voids of zeolite Beta with phenethyl-sulfonic acid sites (PE-Betas). These PE-Betas, along with conventional H-Betas, mesoporous phenethyl-sulfonic acid-functionalized SiO2 gel (PE-SiO2), and commercial sulfonic acid catalysts (para-toluenesulfonic acid, Nafion NR50) are evaluated in the hydroxyalkylation/alkylation reaction of 2-methylfuran with acetone. The PE-Betas show superior turnover numbers (TON) due to the combination of high acid site strength and hydrophobicity that arises from the confined PE groups. Further, the hydrophobicity and TON over PE-Betas are invariant with acid site density, showing that these materials effectively decouple the active site density–hydrophilicity relationship that is a fundamental limitation of conventional zeolites. These sulfonic acid-functionalized zeolites represent a distinct class of water-tolerant, strong Bronsted acid catalysts that may be well suited for a wide range of biomass upgrading reactions that generate stoichiometric amounts of liquid water.
AB - The utility of zeolites in biomass upgrading reactions can be limited in cases where stronger Bronsted acidity and/or hydrophobicity are required for effective catalysis. While sulfonated solids/sulfonic acid catalysts can be used in such cases, they forego the advantageous effects of confinement that are afforded by zeolites. Here, acidity, hydrophobicity, and confinement are integrated into a solid material by functionalizing the intrapore voids of zeolite Beta with phenethyl-sulfonic acid sites (PE-Betas). These PE-Betas, along with conventional H-Betas, mesoporous phenethyl-sulfonic acid-functionalized SiO2 gel (PE-SiO2), and commercial sulfonic acid catalysts (para-toluenesulfonic acid, Nafion NR50) are evaluated in the hydroxyalkylation/alkylation reaction of 2-methylfuran with acetone. The PE-Betas show superior turnover numbers (TON) due to the combination of high acid site strength and hydrophobicity that arises from the confined PE groups. Further, the hydrophobicity and TON over PE-Betas are invariant with acid site density, showing that these materials effectively decouple the active site density–hydrophilicity relationship that is a fundamental limitation of conventional zeolites. These sulfonic acid-functionalized zeolites represent a distinct class of water-tolerant, strong Bronsted acid catalysts that may be well suited for a wide range of biomass upgrading reactions that generate stoichiometric amounts of liquid water.
KW - Confinement
KW - Hydrophobicity
KW - Hydroxyalkylation/alkylation
KW - Sulfonic acid-functionalized zeolites
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U2 - 10.1021/acssuschemeng.1c06401
DO - 10.1021/acssuschemeng.1c06401
M3 - Article
AN - SCOPUS:85121036736
SN - 2168-0485
VL - 9
SP - 17120
EP - 17127
JO - ACS Sustainable Chemistry and Engineering
JF - ACS Sustainable Chemistry and Engineering
IS - 50
ER -