Bi Fukun, Zhang Xiaodong, Xiang Shang, Wang Yunyun
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 Aug 1;573:11-20. doi: 10.1016/j.jcis.2020.03.120. Epub 2020 Mar 31.
The effect of Pd loading (0.25, 0.5 and 1.0 wt%) and ZrO support calcined at diverse temperatures (600, 700 and 800 °C) by pyrolysis of UiO-66 was investigated for CO oxidation in this work, respectively. The physicochemical properties of the samples were characterized by various characterization methods. The XRD results exhibited that all ZrO support possessed mixed crystalline phase, the monoclinic ZrO and tetragonal ZrO. And the calcination temperature had a big impact on the composition of ZrO supports. Pyrolysis of UiO-66 at high temperature was favorable for the formation of monoclinic ZrO. Additionally, the introduction of Pd was induced the phase conversion from tetragonal to monoclinic of ZrO. The order of catalytic efficiency was as follows: 0.5Pd/Zr-700 > 0.5Pd/Zr-600 > 0.5Pd/Zr-800. Moreover, 0.5Pd/Zr-700 presented high stability and great reusability. The good catalytic performance of 0.5Pd/Zr-700 was ascribed to the better reduction ability at low temperature and high O/O and Pd/Pd on the surface. Importantly, the reaction pathway of CO oxidation over the 0.5Pd/Zr-700 was exposed.
本工作分别研究了通过UiO - 66热解负载不同钯含量（0.25、0.5和1.0 wt%）以及在不同温度（600、700和800℃）下煅烧的ZrO载体对CO氧化的影响。采用多种表征方法对样品的物理化学性质进行了表征。XRD结果表明，所有ZrO载体均具有混合晶相，即单斜ZrO和四方ZrO。煅烧温度对ZrO载体的组成有很大影响。高温下UiO - 66的热解有利于单斜ZrO的形成。此外，Pd的引入促使ZrO从四方相转变为单斜相。催化效率顺序如下：0.5Pd/Zr - 700 > 0.5Pd/Zr - 600 > 0.5Pd/Zr - 800。此外，0.5Pd/Zr - 700表现出高稳定性和良好的可重复使用性。0.5Pd/Zr - 700良好的催化性能归因于其在低温下更好的还原能力以及表面较高的O/O和Pd/Pd。重要的是，揭示了0.5Pd/Zr - 700上CO氧化的反应途径。
