Preparation of adsorption materials by combustion method: a new approach to the preparation of magnesia doped with trace zirconium

As a very promising material for CO2 capture owing to its appealing properties, such as abundant basic sites and a higher theoretical adsorption capacity, there are a variety of MgO-based adsorbent (MA) preparation methods reported in numerous studies. Zirconia is usually studied as a carrier; however, little research is focused on the preparation of MA by trace ZrO2-doping. Since the preparation of MA is complex and time-consuming, it is imperative to find a facile and efficient method to simplify the preparation process and produce MA with high performance for CO2 capture. In this experiment, salicylic acid was used as a combustion aid to prepare MA with different doping contents of ZrO2. Among the as-obtained samples, under the calcination temperature of 550 degrees C and the calcination time of 160 min, the MA doped with 2% ZrO2 prepared by the combustion of MgO and ZrO2 complexes without washing and a filtration process showed excellent performance. As confirmed by CO2-TPD, the adsorption of CO2 over the adsorbent was mainly chemical adsorption, and the adsorbent that had a larger specific surface area provided numerous surface basic sites. Besides, the micro crystals of MgO were widely separated due to the employment of ZrO2 as a dispersant, avoiding the accumulation of MgO through CO2 adsorption-desorption cycles. This study provides a meaningful idea for the preparation of modified MA for CO2 capture.

Automated summary

MgO-based adsorbents (MA) have abundant basic sites and high theoretical adsorption capacity, making them promising for CO2 capture. This study suggests a simplified method for preparing high-performance MA by doping ZrO2 as a dispersant, preventing the accumulation of MgO.