Keggin型钨硅酸盐二聚体酯锡衍生物的可控合成、表征及催化性能
Controllable synthesis,characterization and catalytic performance of a divacant Keggin-type tungstosilicate dimer-estertin derivative
朱浩天 1张冉冉 1李孟璇 1孙杨 1苏芳 1张澜萃1
作者信息
- 1. 辽宁师范大学化学化工学院,辽宁大连 116029
- 折叠
摘要
采用常规水溶液法合成了一种缺位Keggin型钨硅酸盐二聚体酯锡衍生物(C(NH2)3)7H3.5[K⊂Ni(H2O)2(SnCH2CH2COO)((Ni(H2O))0.75(WO)0.25)(Si2W18O67)]·6H2O(简写为Si2W18-Ni-SnRCOO,R=CH2CH2),并通过一系列物理和光谱方法进行了表征.单晶X射线结构分析表明,这种多金属氧酸盐(POM)是一种二聚钨硅酸盐基有机-无机杂化化合物,含有Ni离子和环状羧基锡(SnRCOO)基团.出乎意料的是,SnRCOO的羧基O原子充当了 POM骨架与NiO6八面体之间的桥O原子.并研究了 Si2W18-Ni-SnRCOO的热催化活性和光催化活性,作为均相催化剂,其催化环己醇氧化为环己酮的转化率高达98％;对20 mg·L-1罗丹明B(RhB)的降解效率达到88％.实验结果表明,引入羧乙基锡基团显著提高了这种POM基催化剂的催化活性.此外,Si2W18-Ni-SnRCOO与TiO2复合使催化剂能够回收利用,其光催化效率在五次循环后几乎保持不变.
Abstract
A lacunary Keggin-type tungstosilicate dimer-estertin derivative,(C(NH2)3)7H3.5[K⊂Ni(H2O)2(SnCH2CH2COO)((Ni(H2O))0.75(WO)0.25)(Si2W18O67)]·6H2 O(abbreviated as Si2W18-Ni-SnR-COO,R=CH2CH2),was synthesized by using the conventional aqueous solution method,and character-ized by a series of physical and spectral methods.Single crystal X-ray structural analysis revealed that the polyoxometalate(POM)was a dimeric tungstosilicate-based organic-inorganic hybrid compound,which contained two Ni ions and a cyclic carboxyltin group(SnRCOO).Unexpectedly,the carboxyl-oxygen at-om of SnRCOO acted as a bridging oxygen atom belonged to the POM skeleton and connected to NiO6 oc-tahedron.The thermal and photocatalytic activities of Si2W18-Ni-SnRCOO were studied.As a homogene-ous catalyst,the conversion of cyclohexanol to cyclohexanone was as high as 98％,and the degradation ef-ficiency of 20 mg·L-1 RhB reached 88％.The experimental results showed that the introduction of the carboxyethyltin group significantly enhanced the catalytic activity of this type of POM-based catalyst.Ad-ditionally,the composite of Si2W18-Ni-SnRCOO and TiO2 enabled the catalyst to be recycled,and the pho-tocatalytic efficiency of Si2W18-Ni-SnRCOO/TiO2 remained almost unchanged after five cycles.
关键词
多金属氧酸盐/钨硅酸酯锡衍生物/晶体结构/氧化催化/光催化Key words
polyoxometalate/tungstosilicate-estertin derivative/crystal structure/oxidation catalysis/pho-tocatalysis引用本文复制引用
出版年
2024
NETL
NSTL
万方数据