Plasma-catalytic dry reforming of methane in an atmospheric dielectric barrier discharge: Understanding the synergistic effect at low temperature
Plasma-catalytic dry reforming of methane in an atmospheric dielectric barrier discharge: Understanding the synergistic effect at low temperature
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DOI：
10.1016/j.apcatb.2012.06.006
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发表时间：
2012-08
影响因子：
22.1
通讯作者：
X. Tu;J. Whitehead
中科院分区：
文献类型：
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作者：
X. Tu;J. Whitehead
在同轴介质阻挡放电（DBD）反应器中，采用不同Ni/γ-Al 2 O3催化剂，对CH 4等离子体催化干重整制合成气进行了研究。三种不同的填充方法被引入到单级等离子体催化系统中，以研究填充到等离子体区域中的催化剂对DBD的物理性质的影响，并确定在等离子体催化干重整反应中随之产生的协同效应。与完全填充的反应器相比，完全填充的反应器由于放电体积的显著减少而强烈改变了放电模式，而部分填充的Ni/γ-Al 2 O3催化剂无论是在径向还是轴向方向上都显示出强烈的惯性放电，并显著增强了等离子体与催化剂之间的物理和化学相互作用。放电的光发射光谱表明在甲烷的等离子体干重整反应中存在反应物种（CO，CH，C2，CO2+和N2+）。同时发现Ni/γ-Al_2O_3催化剂的存在对CH_4/CO_2放电的气体温度影响不大。当10wt%Ni/γ-Al_2 O_3催化剂在300°C下焙烧后部分填充于等离子体中时，可以明显观察到等离子体与催化剂结合的协同效应，甲烷转化率（56.4%）和氢气产率（17.5%）几乎都提高了一倍。等离子体催化的协同作用还有助于显著提高温室气体转化的能源效率。低温等离子体与固体催化剂的协同效应是由于等离子体与催化剂的强相互作用和低温焙烧的Ni/γ-Al 2 O3催化剂的高活性共同作用的结果。
A coaxial dielectric barrier discharge (DBD) reactor has been developed for plasma-catalytic dry reforming of CH4into syngas over different Ni/γ-Al2O3catalysts. Three different packing methods are introduced into the single-stage plasma-catalysis system to investigate the influence of catalysts packed into the plasma area on the physical properties of the DBD and determine consequent synergistic effects in the plasma-catalytic dry reforming reactions. Compared to the fully packed reactor, which strongly changes the discharge mode due to a significant reduction in the discharge volume, partially packing the Ni/γ-Al2O3catalyst either in a radial or axial direction into the discharge gap still shows strong filamentary discharge and significantly enhances the physical and chemical interactions between the plasma and catalyst. Optical emission spectra of the discharge demonstrate the presence of reactive species (CO, CH, C2, CO2+and N2+) in the plasma dry reforming of methane. We also find the presence of the Ni/γ-Al2O3catalyst in the plasma has a weak effect on the gas temperature of the CH4/CO2discharge. The synergistic effect resulting from the integration of the plasma and catalyst is clearly observed when the 10wt% Ni/γ-Al2O3catalyst in flake form calcined at 300°C is partially packed in the plasma, showing both the CH4conversion (56.4%) and H2yield (17.5%) are almost doubled. The synergy of plasma-catalysis also contributes to a significant enhancement in the energy efficiency for greenhouse gas conversion. This synergistic effect from the combination of low temperature plasma and solid catalyst can be attributed to both strong plasma–catalyst interactions and high activity of the Ni/γ-Al2O3catalyst calcined at a low temperature.