Synthesis of ternary magnetic nanoparticles for enhanced catalytic conversion of biomass-derived methyl levulinate into γ-valerolactone

• 作者: Xueli Chen Tingting Zhao Xuesong Zhang Yuxuan Zhang Haitao Yu Qian Lyu Xiwen Jia Lujia Han Weihua Xiao
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（12）
• 页码范围: 430-441
• 页数: 12页
• 语种: 英文

摘要

Conversion of levulinic acid and its esters into versatile y-valerolactone (GVL) is a pivotal and challenging step in biorefineries,limited by high catalyst cost,the use of hydrogen atmosphere,or tedious catalyst preparation and recycling process.Here we have successfully synthesized a ternary magnetic nanoparti-cle catalyst (Al2O3-ZrO2/Fe3O4(5)),over which biomass-derived methyl levulinate (ML) can be quanti-tively converted to GVL with an extremely high selectivity of ＞ 99％ and yield of ～98％ in the absence of molecular hydrogen.Al2O3-ZrO2/Fe3O4(5) incorporates simultaneously inexpensive alumina and zirco-nia onto magnetite support by a facile coprecipitation method,giving rise to a core-shell structure,well-distributed acid-base sites,and strong magnetism,as evidenced by the X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM),transmission electron micro-scopy (TEM),high-angle annular dark-field scanning-TEM (HAADF-STEM),SEM-energy dispersive X-ray spectroscopy (SEM-EDX),temperature-programmed desorption of ammonia (NH3-TPD),temperature-programmed desorption of carbon dioxide (CO2-TPD),pyridine-adsorption infrared spectra(Py-IR),and vibrating sample magnetometry (VSM).Such characteristics enable it to be highly active and easily recycled by a magnet for at least five cycles with a slight loss of its catalytic activity,avoiding a time-consuming and energy-intensive reactivation process.It is found that there was a synergistic effect among the metal oxides,and the high efficiency and selectivity originating from such synergism are evi-denced by kinetic studies.Furthermore,a reaction mechanism regarding the hydrogenation of ML to GVL is proposed by these findings,coupled with gas chromatography-mass spectrometry (GC-MS) analysis.Accordingly,this readily synthesized and recovered magnetic nanocatalyst for conversion of biomass-derived ML into GVL can provide an eco-friendly and safe way for biomass valorization.