Optimization of N2O decomposition activity of CuO-CeO2 mixed oxides by means of synthesis procedure and alkali (Cs) promotion
Optimization of N2O decomposition activity of CuO-CeO2 mixed oxides by means of synthesis procedure and alkali (Cs) promotion
复制标题
DOI：
10.1039/c8cy00316e
复制
发表时间：
2018-05
影响因子：
5
通讯作者：
Maria Lykaki;E. Papista;S. Carabineiro;P. Tavares;M. Konsolakis
中科院分区：
文献类型：
--
作者：
Maria Lykaki;E. Papista;S. Carabineiro;P. Tavares;M. Konsolakis
对CuO-CeO2复合氧化物的局部表面化学进行了微调，以期通过合成工艺和碱促进来合理设计高活性催化剂。特别探讨了碱(Cs)的促进作用对CuO-CeO2复合氧化物的N2O分解活性(即脱N2O过程)的影响，通过制备过程(不同合成路线之间的共沉淀)进行了预优化。研究发现，共沉淀法和碱用量(Cs/nm2为1.0at)的共同优化可以促进N2O的分解和抗O2抑制，与参考CuO-CeO2样品相比，半转化温度(T50)降低了约200℃。通过比表面积测定(BET法)、孔径分布(BJH法)、X射线衍射法(XRD)、氢气程序升温还原(H2-TPR)和X射线光电子能谱(XPS)等方法对催化剂的结构-性能关系进行了研究。结果表明，Cs掺杂样品的优越性主要归因于碱性促进剂对部分还原的Cu+/Ce3+对的电子稳定作用，它们在遵循氧化还原机理的脱N2O过程中起着关键作用。
The fine-tuning of local surface chemistry of CuO–CeO2 mixed oxides by means of synthesis procedure and alkali promotion towards the rational design of highly active catalysts is investigated. In particular, the impact of alkali (Cs) promotion on the N2O decomposition activity (deN2O process) of CuO–ceria mixed oxides, pre-optimized through the preparation procedure (co-precipitation among different synthesis routes), is explored. It was found that the co-optimization of the synthesis procedure (co-precipitation) and alkali loading (1.0 at Cs per nm2) can boost the decomposition of N2O and resistance to O2 inhibition, offering a half-conversion temperature (T50) ca. 200 °C lower, when compared to a reference CuO–CeO2 sample. A complementary characterization study involving surface area determination (BET method), pore size distribution (BJH method), X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS) was undertaken to gain insight into structure–property relationships. The results revealed that the superiority of Cs-doped samples can be mainly attributed to the electronic effect of the alkali promoter towards the stabilization of partially reduced Cu+/Ce3+ pairs, which play a key role in the deN2O process following a redox-type mechanism.