化学链燃烧
合成气
甲烷
掺杂剂
氧气
氧化铁
氧化物
无机化学
催化作用
氧化钴
化学
钴
化学工程
甲烷转化炉
反应性(心理学)
材料科学
兴奋剂
蒸汽重整
有机化学
制氢
医学
替代医学
工程类
光电子学
病理
作者
Mengqing Guo,Zhuo Cheng,Yan Liu,Lang Qin,Josh W. Goetze,Jonathan A. Fan
标识
DOI:10.1016/j.cattod.2019.06.016
摘要
Chemical looping reforming (CLR) is a promising strategy of methane conversion to syngas with low cost and minimal environmental impact. A major challenge for chemical looping reforming systems is the development of oxygen carriers that have high reactivity, high oxygen carrying capacity, and long-term durability. We demonstrate that the addition of a low concentration of cobalt dopant to iron-based oxygen carriers can dramatically enhance the reactivity in CLR processes at low temperatures while maintaining the recyclability. The methane conversion increased by around 300% for Co-doped iron oxide compared to pure iron oxide oxygen carriers from 600 °C to 800 °C. It was found that 2% Co dopant concentration is optimal for methane conversion rate and cost of oxygen carriers at different temperatures. Density functional theory (DFT) calculations reveal that the Co dopant has a short-range effect on the formation of oxygen vacancies. The Co-doping-induced oxygen vacancy significantly reduces energy barriers of CH4 reforming on the surface of iron oxide oxygen carriers, leading to the reactivity enhancement. Our findings provide a pathway to lower the methane reforming temperature in chemical looping systems, while improving the syngas yield with desired oxygen carrier recyclability.
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