A novel application of alpha- and beta-sodium ferrite as a CO2-capturing solid in air with water vapor

作者：Yanase Ikuo^*; Onozawa Shuhei; Ogasawara Kouhei; Kobayashi Hidehiko

来源：Journal of CO2 Utilization, 2018, 24: 200-209.

DOI：10.1016/j.jcou.2017.11.016

• CO2
• Sodium ferrite
• Water vapor
• pH

The CO2 adsorption properties of synthesized sodium ferrites (alpha-NaFeO2 and beta-NaFeO2) under air and CO2 flows with various relative humidity (RH) were investigated. Thermogravimetry (TG) analysis showed the CO2 adsorption reactions of alpha- and beta-NaFeO2 were promoted even at room temperature (RT) by increasing RH even in air with a low CO2 concentration and the CO2 reaction ratio of beta-NaFeO2 was larger than that of alpha-NaFeO2. X-ray photo spectroscopy (XPS), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) clarified that Na2CO3 center dot H2O and NaHCO3 were produced under air and CO2 flows, respectively, and Na1-xFeO2 and alpha-Fe2O3 were produced for alpha- and beta-NaFeO2 after the CO2 adsorption, respectively. The Na+ concentration and pH were rapidly increased by dispersing NaFeO2 into distilled water. It was therefore found that a basic solution was formed on the surface of NaFeO2 by the adsorption of water molecules on the surface, giving rise to the promotion of CO2 adsorption of NaFeO2 at as low as RT in atmospheres with low CO2 concentrations.

• 出版日期2018-3