Plasma-chemical promotion of catalysis for CH4 dry reforming: unveiling plasma-enabled reaction mechanisms.
Plasma-chemical promotion of catalysis for CH4 dry reforming: unveiling plasma-enabled reaction mechanisms.
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DOI：
10.1039/d0cp03127e
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
Zunrong Sheng;Hyun‐Ha Kim;S. Yao;T. Nozaki
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文献类型：
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作者：
Zunrong Sheng;Hyun‐Ha Kim;S. Yao;T. Nozaki
动力学研究表明，在Ni/Al2O3催化剂中加入镧作为促进剂后，在非热等离子体下CH4和CO2的转化率显著提高。为了更好地理解等离子体和催化剂界面现象，我们在等离子体条件下使用原位漫反射红外傅立叶变换光谱（DRIFTS）来阐明非热等离子体激活的反应增强机制。与热催化相比，等离子体活化CO2在La上形成双齿状（1560和1290 cm-1）和单齿状（1425和1345 cm-1）碳酸盐的能力增强了1.7倍。此外，由于非热等离子体相互作用，形成了碳酸氢盐（1655 cm-1）和桥碳酸盐（1720 cm-1）的新峰。热活化CO2和等离子体活化CO2处理后的CO2- tpd研究进一步证实，等离子体活化CO2在高温（500℃）下可促进双齿和单齿碳酸盐生成1.5倍。XRD和EDS分析表明，在配合物La-Ni-Al氧化物上，CO2-La和CHx-Ni之间可能存在原子尺度的相互作用；振动激发co2诱导碳酸盐是提高CH4低温干重整整体性能的关键。
A kinetic study revealed that a Ni/Al2O3 catalyst exhibited a drastic increase in CH4 and CO2 conversion under nonthermal plasma when lanthanum was added to the Ni/Al2O3 catalyst as a promoter. For a better fundamental understanding of the plasma and catalyst interfacial phenomena, we employed in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) under plasma-on conditions to elucidate the nonthermal plasma-enabled reaction enhancement mechanisms. Compared with thermal catalysis, plasma-activated CO2 shows a 1.7-fold enhancement for bidentate (1560 and 1290 cm-1) and monodentate carbonate (1425 and 1345 cm-1) formation on La. Moreover, new peaks of bicarbonate (1655 cm-1) and bridge carbonate (1720 cm-1) were formed due to nonthermal plasma interactions. CO2-TPD study after thermal- and plasma-activated CO2 treatment further confirmed that plasma-activated CO2 enhances bidentate and monodentate carbonate generation with a 1.5-fold promotion at high temperature (500 °C). XRD and EDS analyses suggest that atomic-scale interaction between CO2-La and CHx-Ni is possible over the complex La-Ni-Al oxide; vibrationally excited CO2-induced carbonates provide the key to enhancing the overall performance of CH4 dry reforming at low temperature.