A new porous Zr-containing catalyst with a phenate group: an efficient catalyst for the catalytic transfer hydrogenation of ethyl levulinate to γ-valerolactone

Abstract

ARTICLEThis journal is Catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) to γ-valerolactone (GVL) is a very attractive reaction in the field of biomass transformation. In this work, a new porous Zrcontaining catalyst with phenate group in its structure was prepared by the coprecipitation of 4hydroxybenzoic acid dipotassium salt and ZrOCl 2 (Zr-HBA) in water and characterized by powder X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, and Fourier transform infrared spectroscopy. The Zr-HBA was used as the catalyst for CTH of EL to GVL in the presence of isopropanol, and the effects of temperature, time, and amount of the catalyst on the reaction were studied. It was found that Zr-HBA was very active for the reaction and a GVL yield of 94.4% could be achieved. Meanwhile, the Zr-HBA could be reused at least five times without notable decrease in activity and selectivity. The main reason for the high catalytic activity of the Zr-HBA was that the existence of phenate in the structure of Zr-HBA increased the basicity of the catalyst, which is favourable to the CTH of EL.

Porous, Naturally Derived Hafnium Phytate for the Highly Chemoselective Transfer Hydrogenation of Aldehydes with Other Reducible Moieties

“…As examined by CO 2 temperature‐programmed desorption (TPD), Hf‐Phy has higher basicity than HfO 2 (Figure b), which may be caused by the higher basicity of the phosphate groups . Higher basicity favors activation of the hydroxy group in i PrOH by the basic sites (O 2− ) in the phosphate groups with the aid of Hf 4+ (Scheme ), and this effect could enhance the transfer hydrogenation. Third, as examined by XRD, Hf‐Phy is amorphous with very low crystallinity, whereas HfO 2 shows better crystallinity (Figure c).…”

“…On the basis of the experimental results and literature reports, we propose a possible mechanism for the Hf‐Phy‐catalyzed CTH of aldehydes with ORMs (Scheme ). In the catalytic cycle, the hydroxy group in i PrOH and the aldehyde group in the aldehyde with ORMs are activated by the catalytic sites Hf 4+ −O 2− and Hf 4+ , respectively.…”

Microwave-Assisted Conversion of Levulinic Acid to γ-Valerolactone Using Low-Loaded Supported Iron Oxide Nanoparticles on Porous Silicates

“…Aqueous phase hydrogenation of LA using Mo2C catalysts provided 99% LA conversion with 90% GVL selectivity at 30 bar H2 and 200 °C [27]. The catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) in isopropanol was also reported using a porous Zr-containing catalyst (Zr-HBA) with a phenate group that produced 94.4% GVL [28]. The presence of the phenate group increased the basicity of the catalyst, which significantly favored the CTH process.…”

Catalytic Transfer Hydrogenolysis as an Effective Tool for the Reductive Upgrading of Cellulose, Hemicellulose, Lignin, and Their Derived Molecules

“…Song and co-workers studied some porous Zr-containing catalysts bearing a phenate group in the CTH of EL to GVL [100]. The results show that Zr-HBA is very active for the conversion of EL and the GVL yield of 95.9% can be achieved in the presence of 2-butanol as an H-donor.…”