Zhang Xiaodong, Song Liang, Bi Fukun, Zhang Dongfeng, Wang Yuxin, Cui Lifeng
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China.
J Colloid Interface Sci. 2020 Jul 1;571:38-47. doi: 10.1016/j.jcis.2020.03.031. Epub 2020 Mar 9.
In this paper, dispersed Ag nanoparticles supported on UiO-66 derivative were prepared and the effect of Ag loading on the structure and performance of the catalysts for toluene oxidation were studied. The characteristics of the catalysts were studied by XRD, SEM, TEM, HRTEM, BET, ICP-OES, XPS, UV-vis and in situ DRIFTS. It was observed that UiO-66 structure of 2 wt% Ag catalyst (2Ag-U) was not damaged. When Ag loading was further increased to 10 wt% (10Ag-U), framework of UiO-66 collapsed and uniform Ag nanoparticles were dispersed on the surface of support. Further increasing Ag to 14 wt% (14Ag-U), large Ag nanoparticles were observed, and Ag species migrated to the bulk phase of the support, resulting in the decrease of surface Ag content. The 10Ag-U catalyst showed excellent catalytic performance due to higher lattice oxygen and surface Ag content. In addition, in situ DRIFTS analysis was used to explore toluene-catalyzed intermediates. It was found that toluene was converted to benzaldehyde and benzoic acid, eventually forming CO and HO.
本文制备了负载在UiO-66衍生物上的分散银纳米颗粒，并研究了银负载量对甲苯氧化催化剂结构和性能的影响。通过XRD、SEM、TEM、HRTEM、BET、ICP-OES、XPS、UV-vis和原位DRIFTS对催化剂的特性进行了研究。观察到2 wt% Ag催化剂（2Ag-U）的UiO-66结构未受损。当银负载量进一步增加到10 wt%（10Ag-U）时，UiO-66的骨架坍塌，均匀的银纳米颗粒分散在载体表面。进一步将银增加到14 wt%（14Ag-U）时，观察到较大的银纳米颗粒，并且银物种迁移到载体的体相中，导致表面银含量降低。10Ag-U催化剂由于具有较高的晶格氧和表面银含量而表现出优异的催化性能。此外，采用原位DRIFTS分析来探究甲苯催化中间体。发现甲苯转化为苯甲醛和苯甲酸，最终形成CO和H₂O。
