TY - JOUR
T1 - Acidity-activity relationships in the solvent-free tert-butylation of phenol over sulfated metal oxides
AU - Zuber, Adam
AU - Tsilomelekis, George
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/2/25
Y1 - 2023/2/25
N2 - Sulfated metal oxides have long been reported to exhibit enhanced acidity properties, which in turn affect reactivity. In this study, sulfated SnO2, TiO2 and ZrO2 of varying acidic properties were synthesized and utilized for the solvent-free alkylation of phenol with tert-butyl alcohol. Herein, it was observed that tert-butylation of phenol could be carried out at 120 °C with significant yield towards alkylated products; the majority was accounted for by the mono-alkylated products. Among the catalysts studied, SnO2 with high content of sulfation was found to be the more active. In-situ DRIFTS in the range of 25–500 °C was used to investigate the temperature evolution of sulfate species and differentiate between bidentate and tridentate configurations. By combining temperature-programmed desorption, in-situ DRIFTS and catalytic performance measurements a correlation between the ratio of Lewis to Brønsted acids and overall reactivity was observed.
AB - Sulfated metal oxides have long been reported to exhibit enhanced acidity properties, which in turn affect reactivity. In this study, sulfated SnO2, TiO2 and ZrO2 of varying acidic properties were synthesized and utilized for the solvent-free alkylation of phenol with tert-butyl alcohol. Herein, it was observed that tert-butylation of phenol could be carried out at 120 °C with significant yield towards alkylated products; the majority was accounted for by the mono-alkylated products. Among the catalysts studied, SnO2 with high content of sulfation was found to be the more active. In-situ DRIFTS in the range of 25–500 °C was used to investigate the temperature evolution of sulfate species and differentiate between bidentate and tridentate configurations. By combining temperature-programmed desorption, in-situ DRIFTS and catalytic performance measurements a correlation between the ratio of Lewis to Brønsted acids and overall reactivity was observed.
KW - Lewis/Brønsted acidity
KW - Sulfated metal oxides
KW - tert-butylation of phenol
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U2 - 10.1016/j.apcata.2023.119040
DO - 10.1016/j.apcata.2023.119040
M3 - Article
AN - SCOPUS:85146448728
SN - 0926-860X
VL - 652
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
M1 - 119040
ER -