Conversion of ethyl levulinate to γ‐valerolactone catalyzed by the new Zr‐containing organic–inorganic hybrid catalysts

Abstract

Three novel heterogeneous Zr-containing organic-inorganic hybrid catalysts were prepared for the transfer hydrogenation of biomass-derived ethyl levulinate (EL) to γ-valerolactone (GVL) with isopropyl alcohol (IPA) as the hydrogen donor and were characterized by Fourier transform infrared (FT-IR), Temperature-programmed desorption (TPD), Thermogravimetry (TG), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). On their basis, the effects of temperature, time, the amount of catalyst, and the solvent were investigated on the yield of GVL. A GVL yield of 96.5% with 99% EL conversion was obtained using Zr-Pg, which was prepared by the reaction of ZrCl 4 and phloroglucinol (Pg) in N,N-dimethylformamide (DMF) at room temperature. The high catalytic activity may be attributed to the strong basicity, which was increased by the sufficient quantity of phenate in the structure of Zr-Pg. Meanwhile, Zr-Pg could be efficiently and easily recycled at least five times without any notable loss of activity and selectivity. Through the results of comparative experiments and characterization, we propose a plausible reaction mechanism for the high activity of Zr-Pg. K E Y W O R D Sethyl levulinate, hydrogen donor, transfer hydrogenation, Zr-Pg, γ-valerolactone

Catalytic Transfer Hydrogenation of Furfural to Furfuryl Alcohol under Mild Conditions over Zr-MOFs: Exploring the Role of Metal Node Coordination and Modification

“…Moreover, a strategy to enhance catalytic activity through metal node modification of Zr-MOFs has not yet been implemented for the transfer hydrogenation of biomass carbonyls. Most importantly, a variety of heterogeneous catalysts, such as metal oxides, ,, metal hydroxides, ,, metal complexes, ,, metal–organic nanohybrids, ,, mesoporous silica, , supported metals and metal oxides, ,,− zeolites, ,, and MOFs, ,, have been reported for the transfer hydrogenation of biomass-derived carbonyl compounds using alcohol as a hydrogen donor, but none of these heterogeneous catalysts have been shown to be active at or near room temperature. In addition, a number of noble-metal-based catalysts, which are active at room temperature for the hydrogenation of biomass-derived carbonyls using H 2 gas as a hydrogen source, need pressurized reaction systems, − and these demand the use of sophisticated instruments that may incur heavy infrastructural costs on a large scale.…”

Catalytic transfer hydrogenation of furfural into furfuryl alcohol over Ni–Fe‐layered double hydroxide catalysts

“…According to previous reports, acidic sites and basic sites play synergistic catalytic roles in the CTH of carbonyl compounds. Therefore, the acidity and basicity of catalysts were characterized by CO 2 ‐TPD and NH 3 ‐TPD (Figure ), respectively.…”

Highly efficient production of 2,5-dihydroxymethylfuran from biomass-derived 5-hydroxymethylfurfural over an amorphous and mesoporous zirconium phosphonate catalyst

“…1 . The peaks at around 1628 cm −1 and 3386 cm −1 are due to the stretching vibration of surface-adsorbed water [31] . Moreover, it should be noted that the peak at around 2425 cm −1 belongs to the stretching vibration of O − H in free monohydrogen-phosphate group (P − OH) that might be incompletely coordinated with Zr 4 + [32] .…”