构建元素相同晶相不同的Ln_(2)Zr_(2)O_(7)(Ln=Pr,Nd,Sm)催化剂用于甲烷氧化偶联反应  

Construction of Ln_(2)Zr_(2)O_(7)(Ln=Pr,Nd,Sm) catalysts with identical elements and different crystalline phases for oxidation coupling reactions of methane

作　　者：王翔[1] 欧阳汝梦 徐骏伟 钟旭升 周杰祺 WANG Xiang;OUYANG Rumeng;XU Junwei;ZHONG Xusheng;ZHOU Jieqi(School of Chemistry and Chemical Engineering,Nanchang University,Nanchang 330031,China;Department of Applied Chemistry,Jiangxi Academy of Sciences,Nanchang 330096,China)

机构地区：[1]南昌大学化学化工学院,江西南昌330031 [2]江西省科学院应用化学研究所,江西南昌330096

出　　处：《南昌大学学报(工科版)》2025年第1期1-13,共13页Journal of Nanchang University(Engineering & Technology)

基　　金：江西省自然科学基金资助项目(20224BAB213017);国家自然科学基金资助项目(22172071,22102069,22376090)。

摘　　要：采用简单的共沉淀法通过不同焙烧温度制备了3组不同晶相结构和晶格无序度的Ln_(2)Zr_(2)O_(7)(Ln=Pr,Nd,Sm)复合氧化物催化剂,用于探究其对甲烷氧化偶联反应的影响。结果表明:A_(2)B_(2)O_(7)复合氧化物的化学组成相同、晶相结构和晶格无序程度不同时,晶相结构和晶格无序是影响其反应性能的重要因素,A_(2)B_(2)O_(7)复合氧化物表面中等强度碱中心和强碱中心的量以及O_(2)^(-)/O^(2-)比例的大小排序为萤石相>过渡相>烧绿石相。当晶相结构和晶格无序度相同、化学组成不同时,A位离子氧化物(稀土氧化物)碱性强弱是影响其反应性能的重要因素,A_(2)B_(2)O_(7)复合氧化物表面中等强度碱中心和强碱中心的量以及O_(2)^(-)/O^(2-)比例遵循Nd_(2)Zr_(2)O_(7)>Sm_(2)Zr_(2)O_(7)>Pr_(2)Zr_(2)O_(7)的顺序。A_(2)B_(2)O_(7)复合氧化物的C_(2)选择性与氧物种O_(2)^(-)和碱中心密切相关。Three groups of Ln_(2)Zr_(2)O_(7)(Ln=Pr,Nd,Sm) catalysts with different crystal phase structures and lattice disorder degrees were prepared by simple co-precipitation method and calcination at different temperatures to unfold the influence for oxidative coupling of methane reaction.It was found that when the chemical composition of A_(2)B_(2)O_(7) composite oxides was the same,the crystal phase structure and lattice disorder degree were different,the crystal phase structure and lattice disorder were important factors affecting their reaction performance.The amounts of moderate and strong base sites on the surfaces of A_(2)B_(2)O_(7) composite oxides,as well as the ratio of O_(2)^(-)/O^(2-)followed the order of Fluorite>Transitional>Pyrochlore crystalline phases.When the crystal phase structure and lattice disorder degree of A_(2)B_(2)O_(7) composite oxides were the same,the chemical composition was different,the basicity of rare earth oxide and the properties of A-site element were important factors affecting their reaction performance.The amounts of moderate and strong base sites on the surfaces of A_(2)B_(2)O_(7) composite oxides,as well as the ratio of O_(2)^(-)/O^(2-)followed the order of Nd_(2)Zr_(2)O_(7)>Sm_(2)Zr_(2)O_(7)>Pr_(2)Zr_(2)O_(7).The C_(2) selectivity of A_(2)B_(2)O_(7) composite oxides was highly correlated with the oxygen species O_(2)^(-)and base sites.

关 键 词：甲烷氧化偶联反应 A_(2)B_(2)O_(7)复合氧化物 晶相结构 晶格无序度 活性氧中心 碱中心 

分 类 号：O643[理学—物理化学]