高活性Cu-ZnO@SiO_(2)纳米催化剂催化CO_(2)加氢制甲醇  

High-performance Cu-ZnO@SiO_(2) Nano-catalyst for CO_(2) Hydrogenation to Methanol

作　　者：陈浩 陈桂 宋丹丹 曾艳红 刘文虎[3] 张明[4] CHEN Hao;CHEN Gui;SONG Dandan;ZENG Yanhong;LIU Wenhu;ZHANG Ming(College of Bioligical and Environmental Engineering,Yueyang Vocational and Technical College,Yueyang 414000,China;College of Chemistry and Materials Engineering,Huaihua University,Huaihua 418000,China;College of Petrochemical Engineering,Hunan Petrochemical Vocational Technology College,Yueyang 414000,China;College of Mechanical and Electrical Engineering,Hunan Petrochemical Vocational Technology College,Yueyang 414000,China)

机构地区：[1]岳阳职业技术学院生物环境工程学院,岳阳414000 [2]怀化学院化学与材料工程学院,怀化418000 [3]湖南石油化工职业技术学院石化工程学院,岳阳414000 [4]湖南石油化工职业技术学院机电工程学院,岳阳414000

出　　处：《高等学校化学学报》2023年第11期111-119,共9页Chemical Journal of Chinese Universities

基　　金：湖南省自然科学基金(批准号:2023JJ50309,2023JJ50450)资助。

摘　　要：铜基催化剂可被广泛应用于CO_(2)加氢制甲醇,其催化活性高度依赖载体.本文通过St?ber法合成了SiO_(2)纳米微球,将其作为载体制备了Cu-Zn O@Si O_(2)催化剂;将该催化剂应用于CO_(2)加氢制甲醇,并与常规共沉淀法制备的Cu-Zn O催化剂进行了对比.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、氢气程序升温还原(H_(2)-TPR)和二氧化碳程序升温脱附(CO_(2)-TPD)等手段对催化剂进行了表征.结果表明,Cu-Zn O@Si O_(2)催化剂具有更高的Cu分散性和CO_(2)吸附能力,Si O_(2)的加入提高了催化剂表面Cu^(+)/Cu^(0)的比例,从而影响了催化性能.研究发现,在H_(2)/CO_(2)摩尔比为3,230℃,2.0 MPa和气体体积空速为3600 m L·g^(-1)_(cat)·h^(-1)条件下,Cu-Zn O@Si O_(2)催化剂具有更高的催化活性(甲醇选择性88.2%,甲醇收率11.1%),远高于Cu-Zn O催化剂(甲醇选择性36.5%,甲醇收率6.9%).原位红外光谱(DRIFT)分析表明,CO_(2)在Cu-ZnO@SiO_(2)催化剂上主要通过RWGS+CO加氢路径生成甲醇.Cu-based catalysts are widely employed for CO_(2) hydrogenation to methanol.However,their catalytic performance highly depends on supports.Herein,the nano-spherical SiO_(2) support was synthesized by the Stöber method and used as a component in Cu-ZnO@SiO_(2) catalyst.The catalyst was tested in hydrogenation of CO_(2) to methanol and compared with the Cu-ZnO catalyst(6.9%yield of methanol and 36.5%selectivity of methanol)prepared via conventional coprecipitation process.It was found that Cu-ZnO@SiO_(2) catalyst exhibits the best catalytic performance,the yield of methanol reached 11.1%with 88.2%selectivity of methanol at n(H_(2))/n(CO_(2))=3,230℃,2.0 MPa and gaseous hourly space velocity(GHSV)=3600 mL·g^(-1)_(cat)·h^(-1).The catalysts were thoroughly characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS),tempera-ture-programmed reduction(H_(2)-TPR)and CO_(2) temperature-programmed desorption(CO_(2)-TPD).The results show that Cu-ZnO@SiO_(2) catalyst has higher Cu dispersion and CO_(2) adsorption capacity,and the addition of SiO_(2) increases the Cu^(+)/Cu^(0) molar ratio on the catalyst surface,which affects the catalytic performance.The characterization analysis of Diffuse reflectance fourier transform infrared spectroscopy(DRIFT)showed that CO_(2) generated methanol on Cu-ZnO@SiO_(2) catalyst mainly through reverse water gas reaction(RWGS)+CO hydrogenation path.

关 键 词：催化剂 二氧化碳加氢 甲醇 

分 类 号：O643.36[理学—物理化学] X773[理学—化学]