摘要
采用共沉淀法制备了一系列Ca-Al-LDHs固体碱催化剂用于非均相催化合成2-硝基-2-甲基-1-丙醇。利用XRD、SEM、XPS、CO_(2)-TPD、FT-IR、BET等分析手段对Ca-Al-LDHs的结构特性、金属价态、碱性强度与催化性能构效关系进行表征,通过2-硝基丙烷与甲醛羟甲基化反应评价了Ca-Al-LDHs固体碱催化剂的催化性能,并对2-硝基-2-甲基-1-丙醇的制备工艺进行了优化。结果表明,所制备的固体碱催化剂表面存在大量强碱性活性位点,并且存在一种新的晶格结构(Ca12Al14O33),该结构的存在提高了该催化剂对羟甲基化反应的催化性能;在温度为70℃、反应时间为2 h、n(甲醛)∶n(2-硝基丙烷)=2∶1、m(催化剂)∶m(甲醛)=3∶10的反应条件下,2-硝基丙烷的转化率为96.2%,2-硝基-2-甲基-1-丙醇选择性为99%。催化剂重复使用20次后,产品收率仍能达到60%以上。
A series of Ca-Al-LDHs solid base catalysts are prepared via common precipitation method,and used for heterogeneous catalytic synthesis of 2-nitro-2-methyl-1-propionol.The relationships between the structural characteristics,metal valence state,alkaline intensity respectively and catalytic performance of Ca-Al-LDHs are characterized by means of XRD,SEM,XPS,CO_(2)-TPD,FT-IR,BET and other measurements.The catalytic performance of Ca-Al-LDHs is evaluated through the hydroxymethylation reaction between 2-nitropropane and formaldehyde,and the preparation process of 2-nitro-2-methyl-1-propane is also optimized.It is shown there is a large amount of strong alkaline activity sites on the surface of the prepared Ca-Al-LDHs.Ca12Al14O33,a new lattice structure,exists and improves the catalytic performance of the catalyst in hydroxymethylation.The conversion rate of 2-nitropropane reaches 96.2%,and the selectivity of 2-nitro-2-methyl-1-propyol reaches 99%when the temperature is 70℃,the reaction lasts for 2 hours,n(formaldehyde)∶n(2-nitratepropionide)=2∶1,and m(catalyst)∶m(formaldehyde)=3∶10.The product yield can still exceed 60%after the catalyst has been reused for 20 times.
作者
贺胜臣
杨海玉
王昊
王平
楚庆岩
HE Sheng-chen;YANG Hai-yu;WANG Hao;WANG Ping;CHU Qing-yan(School of Chemistry and Chemical Engineering,Shandong University of Technology,Zibo 255000,China)
出处
《现代化工》
CAS
CSCD
北大核心
2024年第3期152-159,共8页
Modern Chemical Industry
基金
山东省自然科学基金面上项目(ZR2020MB130)。
