Selective reduction of carbon dioxide into amorphous carbon over activated natural magnetite
来源期刊：International Journal of Minerals Metallurgy and Materials2021年第2期
论文作者：Zhong-qing Liu Jian Zheng Yi Wang Xu Liu
文章页码：231 - 237
摘 要：Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H2 reduction. The temperature-programmed reduction of hydrogen（H2-TPR） and temperature-programmed surface reaction of carbon dioxide（CO2-TPSR） were carried out to investigate the processes of oxygen loss and CO2 reduction. The samples were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, and energy-dispersive X-ray spectroscopy（EDS）. The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H2 atmosphere. Meanwhile, the activity and selectivity of CO2 reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO2 reduction at 300°C for 90 min over the activated natural magnetite was 2.87 wt% higher than that over the natural magnetite.
Zhong-qing Liu，Jian Zheng，Yi Wang，Xu Liu
School of Chemical Engineering, Sichuan University
摘 要：Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H2 reduction. The temperature-programmed reduction of hydrogen（H2-TPR） and temperature-programmed surface reaction of carbon dioxide（CO2-TPSR） were carried out to investigate the processes of oxygen loss and CO2 reduction. The samples were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, and energy-dispersive X-ray spectroscopy（EDS）. The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H2 atmosphere. Meanwhile, the activity and selectivity of CO2 reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO2 reduction at 300°C for 90 min over the activated natural magnetite was 2.87 wt% higher than that over the natural magnetite.
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