N2O catalytic decomposition over various spinel-type oxides
N2O catalytic decomposition over various spinel-type oxides
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DOI：
10.1016/j.cattod.2006.08.012
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发表时间：
2007-01
期刊：
影响因子：
5.3
通讯作者：
N. Russo;D. Fino;G. Saracco;V. Specchia
中科院分区：
文献类型：
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作者：
N. Russo;D. Fino;G. Saracco;V. Specchia
制备了多种尖晶石型催化剂AB_2 O_4（其中A=Mg，Ca，Mn，Co，Ni，Cu，Cr，Fe，Zn，B=Cr，Fe，Co），并用XRD，BET，TEM和FESEM-EDS等手段对催化剂进行了表征。在程序升温反应（TPR）装置中，考察了在无氧和有氧条件下，催化剂对N2 O分解为N2和O2的催化性能。发现在B位点含有Co的尖晶石型氧化物提供最佳活性。一氧化二氮在MgCo 2 O 4催化剂上的半转化温度在不存在和存在氧气的情况下分别为440°C和470°C（GHSV=80，000 h-1）。程序升温氧脱附（TPD）分析的理由，以及反应运行，普遍的活性的MgCo 2 O 4催化剂可以解释其较高浓度的表面，弱化学吸附的氧物种，其相关的空位有助于积极的一氧化二氮催化分解。这表明了开发新的、更活性的催化剂的方法，该催化剂可能能够在低温下递送甚至高于MgCo 2 O 4的特征的这些氧物质的量。
Various spinel-type catalysts AB2O4(where A=Mg, Ca, Mn, Co, Ni, Cu, Cr, Fe, Zn and B=Cr, Fe, Co) were prepared and characterized by XRD, BET, TEM and FESEM-EDS. The performance of these catalysts towards the decomposition of N2O to N2and O2was evaluated in a temperature programmed reaction (TPR) apparatus in the absence and the presence of oxygen. Spinel-type oxides containing Co at the B site were found to provide the best activity. The half conversion temperature of nitrous oxide over the MgCo2O4catalyst was 440°C and 470°C in the absence and presence of oxygen, respectively (GHSV=80,000h−1). On the grounds of temperature programmed oxygen desorption (TPD) analyses as well as of reactive runs, the prevalent activity of the MgCo2O4catalyst could be explained by its higher concentration of suprafacial, weakly chemisorbed oxygen species, whose related vacancies contribute actively to nitrous oxide catalytic decomposition. This indicates the way for the development of new, more active catalysts, possibly capable of delivering at low temperatures amounts of these oxygen species even higher than those characteristic of MgCo2O4.