Mechanism of NO2 storage in ceria studied using combined in situ Raman/FT-IR spectroscopy.
Mechanism of NO2 storage in ceria studied using combined in situ Raman/FT-IR spectroscopy.
复制标题
DOI：
10.1039/c3cp51441b
复制
发表时间：
2013-05
期刊：
影响因子：
--
通讯作者：
Anastasia Filtschew;Dominic Stranz;C. Hess
中科院分区：
文献类型：
--
作者：
Anastasia Filtschew;Dominic Stranz;C. Hess
采用原位拉曼光谱法结合定量FT-IR气相分析，对二氧化氮在铈中的储存机理进行了研究。在室温下，NO2暴露会导致铈还原程度的立即增加，并伴随硝酸盐的形成。确定了硝酸盐形成的两个平行反应途径。蒸汽的存在通过有利于自由硝酸盐的形成而不是双齿/桥接硝酸盐的形成，强烈地影响了储存行为。在200°时，自由硝酸盐的生成和气相NO的生成速度加快，而氧化铈的NOx存储容量从0.27 mmol g(-1) CeO2降低到0.16 mmol g(-1) CeO2。
In situ Raman spectroscopy combined with quantitative FT-IR gas phase analysis was used to elucidate the mechanism of NO2 storage in ceria. At room temperature, NO2 exposure induces an immediate increase in the degree of ceria reduction accompanying nitrate formation. Two parallel reaction pathways for nitrate formation are identified. The presence of steam strongly influences the storage behavior by favoring the formation of free nitrates over bidentate/bridging nitrates. At 200°, faster free nitrate formation and gas phase NO formation is observed, while the NOx storage capacity of ceria is reduced from 0.27 to 0.16 mmol g(-1) CeO2.