摘要
采用完全液相-溶剂热法制备Cu-Zn-Al催化剂,通过老化方式调变前驱体的晶相,利用XRD、N_2吸附-脱附、H_2程序升温还原和NH_3程序升温脱附等方法对催化剂进行表征,并在浆态床反应器中测试催化剂的CO加氢催化性能,考察前驱体结晶度对催化剂结构和催化性能的影响。实验结果表明,前驱体的结晶度高,即Cu、Zn组分主要以碱式硝酸盐的晶体形式存在,溶剂热处理时自生压低,有利于Cu物种的分散,从而提高催化剂的CO加氢活性;前驱体结晶度低时自生压高,有利于ZnAl_2O_4尖晶石和较大颗粒Cu的形成,催化剂孔径和孔体积较大,且易形成Cu^+和Cu^0共存的状态,有利于C_2+OH的生成,但CO转化率较低。
Cu-Zn-Al catalysts were prepared by complete liquid-solvothermal method.,with the aim of investigating the influence of the crystallinity of precursor on the structure and catalytic performance by modifying aging codition.The catalysts were characterized by XRD,N2 adsorption-desorption,H2-TPR and NH3-TPD.The performances of the catalysts for CO hydrogenation were evaluated in a slurry bed.The results indicate that if a precursor shows higher crystallinity,that is,the Cu and Zn components mainly exist in the form of basic nitrate,the self-generated pressure was lower during heat treatment,which was beneficial to the dispersion of Cu species and the CO hydrogenation activity of the catalyst.On the contrary,the higher self-generated pressure due to a lower crystallinity of the precursor is conducive to the formation of ZnAl2 O4 spinel and relatively larger particles of Cu,getting larger pore size and pore volume,and easily forming the coexistence of Cu~+and Cu^0,which is favorable for the formation of C(2+)OH,but the CO conversion is low.
作者
任宏伟
黄利
樊金串
黄伟
REN Hong-wei;HUANG Li;FAN Jin-chuan;HUANG Wei(College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024;Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
2018年第5期37-42,105,共7页
Natural Gas Chemical Industry
基金
国家自然科学基金(21336006)
