Simultaneous production of hydrogen and carbon nanotubes from biogas: On the effect of Ce addition to CoMo/MgO catalyst
Simultaneous production of hydrogen and carbon nanotubes from biogas: On the effect of Ce addition to CoMo/MgO catalyst
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DOI：
10.1016/j.ijhydene.2021.09.068
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发表时间：
2021-10-25
影响因子：
7.2
通讯作者：
Ratchahat, Sakhon
中科院分区：
文献类型：
--
作者：
Kludpantanapan, Thunyathon;Nantapong, Paveenuch;Ratchahat, Sakhon
在本研究中，以沼气为原料，通过二氧化碳甲烷化和化学气相沉积的协同组合工艺，同时制备了氢气和碳纳米管。甲醇法可将含有CO2的沼气转化为富含CH4的气体，再分解成H-2，并在CoMo/MgO催化剂上通过CVD过程生成碳纳米管。研究了Ce的添加对CoMo/MgO的影响。综合表征证实，所有合成的样品都是由排列良好的多壁碳纳米管(MWCNTs)组成，尺寸分布较窄。Ce的加入改善了CoMo在氧化镁上的分散性，使碳纳米管更细小、更均匀。在CoMo/MgO催化剂中加入少量Ce可以提高碳纳米管的产率。较高的Ce加入量会导致碳纳米管的产率下降，这是由于CeO2表面的高碱度和CeO2在催化剂表面的覆盖率较大所致。I-G/I-D随Ce加入量的增加而增大，而比表面积单调减小，归因于纳米管缺陷的减少。此外，这种巧妙的组合工艺可以显著地脱除100%的二氧化碳，同时获得90%的高CH4转化率。与进料流中的H-2相比，H-2的产率可提高30%以上。氢气的产率和纯度均在90%左右。(C)2021年氢能出版物有限责任公司。爱思唯尔有限公司出版。保留所有权利。
In this study, hydrogen and carbon nanotubes (CNTs) are simultaneously produced via a synergistic combined process of CO2 methanation (METH) and chemical vapor deposition (CVD) processes using biogas as a feedstock. METH process could upgrade CO2 containing biogas into CH4-rich gas which then decomposed into H-2 and forming CNTs over CoMo/ MgO catalyst by CVD process. The effects of Ce addition to CoMo/MgO were investigated. Comprehensive characterization confirms that all as-synthesized samples composed of well-aligned multi-walled carbon nanotubes (MWCNTs) with a narrow size distribution. The Ce addition improved CoMo dispersion on MgO, resulting in smaller and uniform CNTs. The small addition of Ce into CoMo/MgO catalyst could enhance the production CNTs yield. The higher Ce addition would, however, result in the CNTs yield decreased, attributed to a high basicity of CeO2 surface and a large coverage of CeO2 on the catalyst surface. The I-G/I-D increased with increased Ce addition, while the surface area mono-tonically decreased, attributed to a decrease in defects of nanotubes. In addition, this wisely combined process could result in a remarkable 100%CO2 elimination, while high CH4 conversion of 90% was obtained. The H-2 production yield could gain more than 30 vol% with respect to H-2 in the feed stream. The H-2 yield and purity in the effluent gas stream were approximately 90%. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.