不同硅铝比HZSM-5担载Pd催化CH_(4)-CO_(2)两步梯阶转化直接合成乙醇的研究  

Direct Synthesis of Ethanol from CH_(4)-CO_(2) by Two-Step Step-up Conversion Catalyzed by Pd in HZSM-5 with Different Si/Al Ratios

作　　者：黄伟[1,2] 李林姝 HUANG Wei;LI Linshu(State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024.China:2.Institute of Advanced Materials and Chemical Engineering,Shanxi Zhejiang University;Taiyuan 030024,China)

机构地区：[1]太原理工大学省部共建煤基能源清洁高效利用国家重点实验室,山西太原030024 [2]山西浙大新材料与化工研究院,山西太原030024

出　　处：《山西大学学报（自然科学版）》2022年第5期1350-1361,共12页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(21975173);山西浙大新材料与化工研究院(2021S-FR009)。

摘　　要：非氢化CO_(2)还原是突破氢制约碳循环利用的有效手段。文章基于自主创新的梯阶转化技术,以硅铝比为18,25,38,50的HZSM-5为载体,以PdCl_(2)为钯源,采用等体积浸渍的方法制备了Pd-ZSM-5系列催化剂,考察了所制催化剂对CH_(4)-CO_(2)两步梯阶转化直接合成乙醇的催化性能,运用X射线衍射(XRD)、N_(2)-吸附脱附、NH_(3)程序升温脱附(NH_(3)-TPD)和X射线光电子能谱(XPS)等表征手段对催化剂的体相结构、比表面积和酸性质进行了分析。结果表明,采用硅铝比为38的HZSM-5制备的Pd-ZSM-5催化剂乙醇的时空收率最高,在常压、150℃的反应条件下,乙醇时空收率为4253.80 mg·mol_(Pd)^(-1)·h^(-1);适当的中强和强酸量及B酸占比有利于乙醇的生成。此外,B酸位还有利于CH的活化和活性组分钯在载体上的分散。Non-hydrogenated COreduction is an effective means to break through hydrogen-constrained of carbon recycling usage.Based on the two-step wise conversion technology of independent innovation,a series of Pd-ZSM-5 catalysts were prepared by constant volume impregnation using HZSM-5 with Si/Al ratio of 18,25,38 and 50 as support and PdCl_(2)as palladium source.The catalytic performance of the catalysts for CH_(4)-CO_(2)two-step step-up conversion into ethanol was investigated.X-ray diffraction (XRD),N-adsorption desorption,NH_(3)temperature-programmed desorption (NH_(3)-TPD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the bulk phase structure,specific surface area and acidity of the catalyst.The results showed that the ethanol yield of Pd-ZSM-5 catalyst prepared by HZSM-5 with Si/Al ratio of 38 was the highest,and the ethanol yield was 4253.80 mg·mol_(Pd)^(-1)·h^(-1)at atmospheric pressure and 150℃.The proper numbers of medium and strong acid as well as the proportion of B acid are favorable for the production of ethanol.In addition,the B acid sites are also conducive to the activation of CHand the dispersion of palladium on the carrier.

关 键 词：Pd-ZSM-5 硅铝比 酸性 乙醇 

分 类 号：O436[机械工程—光学工程]