Effect of pore texture property of mesoporous alumina on adsorption performance of ammonia gas

Abstract

We report that the adsorption of ammonia gas on the synthesized mesoporous alumina (MA) with the controlled pore texture properties were measured. The MA adsorbents with controlled pore properties were synthesized by the Evaporation Induced Self Assembly (EISA) method. It was found that the pore size, and surface area could be adjusted by changing the mole ratio of the acid to alumina precursor during the preparation procedure. When the MA materials were used as adsorbents on ammonia gas adsorption, both adsorption kinetics and capacity were highly influenced by the pore texture properties. Pseudo first order that adsorption kinetic constant and the effective diffusivities of alumina adsorbents decreased with decreasing pore size or increasing surface area, while adsorption capacities increased. In order to estimate the adsorption behavior of ammonia gas, the Langmuir, Freundlich, Sips, and Toth isotherm models were employed. Langmuir model-based calculation reveals that mesoporous alumina MA-1.1 adsorbent with a large surface area and a small pore size shows the best performance in terms of the calculated maximum adsorption capacity of ammonia (193.57 mg/g), which is almost double that of other MA adsorbents (MA-3.3, MA-4.4) and 2.89 times that of commercial γ-Al2O3.