In operando Detection of Three-Way Catalyst Aging by a Microwave-Based Method: Initial Studies
In operando Detection of Three-Way Catalyst Aging by a Microwave-Based Method: Initial Studies
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DOI：
10.3390/app5030174
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发表时间：
2015-09-01
影响因子：
2.7
通讯作者：
Moos, Ralf
中科院分区：
文献类型：
--
作者：
Beulertz, Gregor;Votsmeier, Martin;Moos, Ralf
对微波谐振腔微扰法检测三效催化剂老化进行了初步研究。两种物理化学效应与老化状态相关。在高温下，氧化催化剂的共振频率（λ = 1.02）不受老化的影响，但在还原情况下（λ = 0.98）受老化的显著影响。因此，催化剂老化状态可以潜在地从还原态和氧化态之间的共振频率差或从λ振荡期间的共振频率幅度来推断。其次，在低温下吸附的水强烈影响共振频率。起燃实验研究表明，在低于储氧起燃的温度下，共振频率取决于老化状态。这些差异归因于不同老化样品的不同吸水能力，这是由于表面积随着老化的进行而减小。除老化状态外，原料气中的水含量和温度影响吸附水的量，导致催化剂的整体电材料性质不同，并改变催化剂填充罐的共振性质。催化剂的经典老化相关性质（储氧能力、储氧起燃、表面积）与通过基于微波的方法获得的数据非常一致。
Initial studies on aging detection of three way catalysts with a microwave cavity perturbation method were conducted. Two physico-chemical effects correlate with the aging state. At high temperatures, the resonance frequencies for oxidized catalysts (lambda = 1.02) are not influenced by aging, but are significantly affected by aging in the reduced case (lambda = 0.98). The catalyst aging state can therefore potentially be inferred from the resonance frequency differences between reduced and oxidized states or from the resonance frequency amplitudes during lambda oscillations. Secondly, adsorbed water at low temperatures strongly affects the resonance frequencies. Light-off experiment studies showed that the resonance frequency depends on the aging state at temperatures below the oxygen storage light-off. These differences were attributed to different water sorption capabilities of differently aged samples due to a surface area decrease with proceeding aging. In addition to the aging state, the water content in the feed gas and the temperature affect the amount of adsorbed water, leading to different integral electrical material properties of the catalyst and changing the resonance properties of the catalyst-filled canning. The classical aging-related properties of the catalyst (oxygen storage capacity, oxygen storage light-off, surface area), agreed very well with data obtained by the microwave-based method.