Efficient adsorption of CO2 by amino-functionalized short pore SBA-15: Influence of pore length on adsorption capacity and amino efficiency

Amino-functionalized SBA-15 (AS) with different pore lengths (short pore: 300 nm, SAS and long pore: several tens μm, LAS) were synthesized and applied for CO2 adsorption. The adsorption capacity and amino efficiency affected by pore length, temperature and amino-functionalization were systematically investigated. It was found that CO2 adsorption behavior strongly depended on the pore length, amino-functionalization and adsorption temperature. With decreasing pore length, the adsorption capacity and amino efficiency increased. The amino efficiency increased and the adsorption capacity decreased with increasing temperature. The obtained SAS with short pore exhibited the highest adsorption capacity (1.58, 1.26 and 0.96 mmol CO2/g) and amino efficiency (0.07, 0.19 and 0.27 mol CO2/mol N) under 273, 298 and 323 K at 1 bar, respectively, owing to the high utilization of internal pores. Furthermore, the obtained adsorbents showed good temperature adaptability and reusability. The results demonstrated the potential of the obtained adsorbents for CO2 adsorption.