摘要
以碱土金属通过共沉淀法改性CuZrO_(2)催化剂,制得了不同碱土金属改性的M-CuZrO_(2)催化剂(M=Mg、Ca、Sr和Ba),并将其用于催化乙醇一步法制备酮类化合物的反应中。采用BET、XRD、氢气程序升温还原(H_(2)-TPR)、乙醇程序升温表面反应(乙醇-TPSR)、CO_(2)程序升温脱附(CO_(2)-TPD)以及XPS对催化剂的体相结构、性质进行了研究。结果表明,以碱土金属Ba改性的Ba-CuZrO_(2)催化剂上Cu 2p_(3/2)结合能较高,有利于乙醇分子中O—H键断裂形成乙醛,且该催化剂表面乙醛脱附量最大、中强碱性位(晶格氧)碱性最强,明显促进了缩合反应的进行。在350℃、0.1 MPa、N_(2)为载气、气时空速(GHSV)为2000 h^(–1)、乙醇进样量为1.8 mLC2H5OH/(mL_(cat)·h)的条件下,Ba-CuZrO_(2)催化剂上乙醇转化率和酮类产物选择性最高,分别为98.1%和51.1%,且在45 h内具有较好的催化稳定性。
M-CuZrO_(2)catalysts(M=Mg,Ca,Sr and Ba)were prepared by modification of CuZrO_(2) catalysts with different alkaline-earth metals via co-precipitation method,and then employed to catalyze the one-step synthesis of ketones from ethanol.The structure and properties of catalysts obtained were characterized and analyzed by BET,XRD,H_(2)-TPR,ethanol-TPSR,CO_(2)-TPD and XPS.The results showed that Ba-CuZrO_(2) catalyst exhibited higher Cu 2p_(3/2) electron binding energy,which was in favor of the O—H bond breakage in ethanol molecules to acetaldehyde formation.Moreover,Ba-CuZrO_(2) catalyst displayed largest acetaldehyde desorption and strongest alkalinity of medium strength alkaline site(lattice oxygen),which demonstrated a significant promotion effect on the condensation reaction.Under reaction conditions of 350℃,0.1 MPa,N_(2)as carrier gas,GHSV 2000 h^(–1) and ethanol feed of 1.8 mLC2H5OH/(mLcat·h),catalysis with Ba-CuZrO_(2) achieved highest ethanol conversion rate and ketone product selectivity,98.1%and 51.1%respectively.Moreover,Ba-CuZrO_(2) catalyst maintained stable catalytic activity within 45 h.
作者
魏玲
曾春阳
解红娟
武应全
WEI Ling;ZENG Chunyang;XIE Hongjuan;WU Yingquan(Public Experimental Center,Taiyuan University,Taiyuan 030032,Shanxi,China;China Petroleum ChemicalIndustry Federation,Beijing 100723,China;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,Shanxi,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2022年第8期1662-1667,共6页
Fine Chemicals
基金
山西省高等学校科技创新项目(2021L577)
山西省自然科学基金(20210302123009)。
