A facile synthesis of α-zirconium phosphate(ZP) nanoparticles as an effective, eco-friendly, and recyclable solid acid catalyst is reported. Polyvinylpyrrolidone(PVP) and polyvinyl alcohol(PVA) were used as organic m...A facile synthesis of α-zirconium phosphate(ZP) nanoparticles as an effective, eco-friendly, and recyclable solid acid catalyst is reported. Polyvinylpyrrolidone(PVP) and polyvinyl alcohol(PVA) were used as organic matrix as dispersing agents and served as a template for the nanoparticles. Hydrogen bonds between ZP and PVA or PVP, along the polymer chains, appear to play an important role for improving the dispersion of in situ formed ZP. Following calcination of PVA/ZP or PVP/ZP, pure hexagonal ZP nanoparticles were obtained. The catalysts were characterized by nitrogen sorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy, and transmission electron microscopy. Pyridine-FTIR and temperature-programmed desorption of NH3 suggest the presence of Brnsted acid sites. The acidic properties of the catalyst were studied in Friedel-Crafts alkylation of phenol by tert-butanol, producing 2-tert-butylphenol, 4-tert-butylphenol, and 2,4-ditert-butylphenol. The alkylation reaction was performed in the presence of catalysts P2O5/Al2O3, P2O5/SiO2, α-ZrP(prepared in the absence of the polymers), and various ionic liquids. The use of the hexagonal ZP nanoparticle catalyst afforded an excellent phenol conversion(86%) and selectivity towards 4-tert-butylphenol(83%) under optimized reaction conditions. The catalyst was easily recovered from the reaction mixture, regenerated, and reused at least four times without significant loss in the catalytic activity.展开更多
日本东京理工大学（Tokyo Institute of Teehnology）化学资源实验室的研究人员说，硫酸是常用的工业催化剂，但使用时会产生大量的废水（还伴有热能损失），为此研究人员曾花费大力气寻找其替代品。到目前为止，如有机酸、无机固体氧...日本东京理工大学（Tokyo Institute of Teehnology）化学资源实验室的研究人员说，硫酸是常用的工业催化剂，但使用时会产生大量的废水（还伴有热能损失），为此研究人员曾花费大力气寻找其替代品。到目前为止，如有机酸、无机固体氧化物杂化物和强酸型阳离子交换树脂等替代品由于价格高或是新制成的催化剂性能差而未能在工业上应用。展开更多
基金We gratefully acknowledge the funding support received for this project from the Isfahan University of Technology (IUT), IR Iran. Further financial support from the Center of Excellence in Sensor and Green Chemistry Research (IUT) is gratefully acknowledged.
文摘A facile synthesis of α-zirconium phosphate(ZP) nanoparticles as an effective, eco-friendly, and recyclable solid acid catalyst is reported. Polyvinylpyrrolidone(PVP) and polyvinyl alcohol(PVA) were used as organic matrix as dispersing agents and served as a template for the nanoparticles. Hydrogen bonds between ZP and PVA or PVP, along the polymer chains, appear to play an important role for improving the dispersion of in situ formed ZP. Following calcination of PVA/ZP or PVP/ZP, pure hexagonal ZP nanoparticles were obtained. The catalysts were characterized by nitrogen sorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy, and transmission electron microscopy. Pyridine-FTIR and temperature-programmed desorption of NH3 suggest the presence of Brnsted acid sites. The acidic properties of the catalyst were studied in Friedel-Crafts alkylation of phenol by tert-butanol, producing 2-tert-butylphenol, 4-tert-butylphenol, and 2,4-ditert-butylphenol. The alkylation reaction was performed in the presence of catalysts P2O5/Al2O3, P2O5/SiO2, α-ZrP(prepared in the absence of the polymers), and various ionic liquids. The use of the hexagonal ZP nanoparticle catalyst afforded an excellent phenol conversion(86%) and selectivity towards 4-tert-butylphenol(83%) under optimized reaction conditions. The catalyst was easily recovered from the reaction mixture, regenerated, and reused at least four times without significant loss in the catalytic activity.
文摘日本东京理工大学（Tokyo Institute of Teehnology）化学资源实验室的研究人员说，硫酸是常用的工业催化剂，但使用时会产生大量的废水（还伴有热能损失），为此研究人员曾花费大力气寻找其替代品。到目前为止，如有机酸、无机固体氧化物杂化物和强酸型阳离子交换树脂等替代品由于价格高或是新制成的催化剂性能差而未能在工业上应用。
