Magnetically separable sulfated zirconia as highly active acidic catalysts for selective synthesis of ethyl levulinate from furfuryl alcohol

Abstract

Magnetically separable sulfated zirconia catalysts were prepared by a two-step approach.

Sulfated Zirconia with Different Crystal Phases for the Production of Ethyl Levulinate and 5‐Hydroxymethylfurfural

“…For T‐ZrO 2 and M‐ZrO 2 , only characteristic peaks between 850 and 450 cm −1 were observed, and they were assigned to zirconia of different crystal phases, which was consistent with the XRD results (Figure S1, Supporting Information). The sulfonated M‐ZrO 2 catalysts show the characteristic peaks at 1323, 1289, 1111, 1051, 1015, and 975 cm −1 (Figure a), which was related to the inorganic bridged bidentate sulfate ion coordinated to Zr 4+ cation in M‐ZrO 2 . Sulfonated T‐ZrO 2 catalysts similarly displayed the characteristic peaks of inorganic bridged bidentate sulfate ion with Zr 4+ cation in T‐ZrO 2 , which confirmed the successful grafting of sulfur species on the surface of ZrO 2 .…”

“…The functionalities on the surface of the bare ZrO 2 and the SO 4 2− /ZrO 2 samples were further characterized using FT‐IR, and the results are shown in Figure . The characteristic peaks at 3450 cm −1 could be assigned to the hydroxyl group in ZrO 2 and that in the coordinated water . The absorption peak at 1630 cm −1 was related to the H—OH bond bending vibration .…”

“…The presence of both Brønsted and Lewis acid sites was observed over the two catalysts. The bands at 1639 and 1539 cm −1 were related to Brønsted acid sites, whereas the bands at 1609 and 1445 cm −1 were assigned to Lewis acid sites . The peak at 1489 cm −1 represented both the Brønsted acid sites and Lewis acid sites .…”

“…The NH 3 ‐TPD pattern of the 500‐T‐1.5 catalyst exhibits two desorption peaks centering from 300 to 700 °C, respectively. Generally, the peaks in the range of 120–300 °C are related to weak acidic sites, the peaks generated at 300–500 °C are related to moderate acidic sites, and the peaks above 500 °C are related to strong acidic sites . The 500‐T‐1.5 catalyst possessed moderate‐to‐strong acidic sites (Table ).…”

Synergy of B and Al Dopants in Mesoporous MFI Nanocrystals for Highly Selective Alcoholysis of Furfuryl Alcohol into Ethyl Levulinate

“…A variety of biomass‐based platform compounds, such as ethanol, furfural, furfuryl alcohol, and levulinic acid, can be obtained from raw biomass . Furthermore, catalytic and sustainable transformation of these platform molecules into highly value‐added compounds, exemplified with the alcoholysis of furfuryl alcohol to ethyl levulinate in this work, mainly depend on the rational design of effective acid catalysts …”