Adsorption of CO2 on PbO at ambient temperature

The adsorption of CO2 on metal oxides at ambient temperature received less study largely due to the small adsorption amount. However, the adsorption is of interest in refreshing the atmosphere of isolated spaces. It was shown in the present work that PbO was sensitive to low concentration CO2 in the presence of water. An XPS examination indicated that PbO changed to PbCO3 after the adsorption of CO2; therefore, the adsorption is chemical in nature. In order to enlarge the CO2 capacity, PbO was dispersed on the surface of a silica gel with large surface area (710 m2/g). Both CO2 capacity and adsorption rate indicated that the optimal dispersion manner of PbO is the mono-molecular layer surface coverage. Breakthrough experiments showed that the prepared adsorbent could effectively capture low-concentration CO2 at ambient temperature and pressure yielding a CO2 capacity of 59.1 mg g−1. The saturated adsorbent was regenerated on heating at 380 °C and the CO2 capability was recovered.