Effects of La-doping and preparation conditions on magnesia-based adsorption materials prepared by salicylic acid complex-combustion method for CO2 capture

Here, salicylic acid (SA) was employed as the complex-combustion aid to prepare MgO-based adsorbents (MBA) for CO2 capture. The influences of different doping content of La, calcination time and temperature, and the mole ratio of SA to metal nitrates on physico-chemical properties and CO2 adsorption capacity of as-obtained MBA were studied in detail. Under the calcination temperature lower than 550 oC and the time of 120 min, the MBA doped with 2% La showed excellent performance. As confirmed, the adsorbent which had larger surface area provided more number of basic sites. Besides, more oxygen vacancies and adsorbed OH species efficiently improved the strength of surface basicity. Finally, the micro crystals of MgO were widely separated and the durability was enhanced greatly in CO2 adsorption-desorption multiple cycles both in industrial carbon dioxide and simulated flue gas due to the dispersing of La species and the employment of SA.

Automated summary

Salicylic acid (SA) was used as a complex-combustion aid to prepare MgO-based adsorbents (MBA) for CO2 capture. The research investigated the effects of different La doping content, calcination time and temperature, and the mole ratio of SA to metal nitrates on the physico-chemical properties and CO2 adsorption capacity of the MBA. The MBA doped with 2% La showed excellent performance with a calcination temperature lower than 550 oC and a time of 120 min. The study confirmed that a larger surface area provided more basic sites and enhanced surface basicity through the presence of oxygen vacancies and adsorbed OH species. Additionally, the dispersion of La species and the use of SA greatly improved the durability and CO2 adsorption capacity of the MBA in multiple cycles.