Superior catalytic activity of a Pd catalyst in methane combustion by fine-tuning the phase of ceria-zirconia support
Superior catalytic activity of a Pd catalyst in methane combustion by fine-tuning the phase of ceria-zirconia support
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DOI：
10.1016/j.apcatb.2020.118631
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发表时间：
2020-06-05
影响因子：
22.1
通讯作者：
Zhan, Wangcheng
中科院分区：
文献类型：
--
作者：
Ding, Yuanqing;Wu, Qingqing;Zhan, Wangcheng
甲烷是温室气体中的一种，其最有效的控制方法是催化燃烧。本文合成了具有高比表面积、不同物相(kappa、appa和四方相)的CeZrO4固溶体，并将其用于甲烷燃烧负载型Pd催化剂的制备。与四方相CeZrO4载体(t-CZ)相比，Kappa-CeZrO4载体(Kappa-CZ)上PdOx颗粒较小，PdO活性物种较多，从而使Pd/Kappa-CZ催化剂具有较高的甲烷活化能力。更重要的是，Pd/t-CZ催化剂的氧迁移率远高于Pd/t-CZ催化剂。因此，与Pd/t-CZ催化剂相比，Pd/kappa-CZ催化剂上的PdO物种具有良好且稳定的氧化还原循环，从而促进了烃类碎片的氧化。这两个因素导致了Pd/kappa-CZ催化剂对甲烷燃烧具有良好的催化活性。
Methane, one of the greenhouse gases, is controlled by the catalytic combustion that is the most efficient method. Herein, ceria-zirconia solid solutions (CeZrO4) with high specific surface areas and different phases (kappa appa and tetragonal) were synthesized and then used to construct the supported Pd catalyst for methane combustion. Compared to the tetragonal CeZrO4 support (t-CZ), the smaller particle sizes of PdOx and the higher amount of active PdO species are present on the kappa appa CeZrO4 support (kappa-CZ), leading to a higher ability of the Pd/kappa-CZ catalyst for methane activation. More critically, the oxygen mobility of the Pd/t-CZ catalyst is much higher than that of the Pd/t-CZ catalyst. Consequently, an excellent and stable redox cycle of PdO species is achieved on the Pd/kappa-CZ catalyst compared to the Pd/t-CZ catalyst, prompting the oxidation of hydrocarbon fragments. These two factors result into a superior catalytic activity of the Pd/kappa-CZ catalyst for methane combustion.