Effect of Ethanol Treatment and Calcination Temperature on Water Vapor Adsorption properties of MCM-41.

MCM-41, a mesoporous material with a high surface area and tunable pore size, shows great potential for water vapor adsorption. However, due to its large pore size, the effective adsorption capacity at medium to low relative partial pressures is limited in adsorption chiller applications. In this work, MCM-41 was successfully synthesized at room temperature using cetyltrimethylammonium bromide (CTAB) as a templating agent. Pore size modulation was achieved by treating the MCM-41 gel with ethanol. The results indicated that ethanol likely exerted an inward force on the pore channels, reducing the pore size from 3.418 to 2.583 nm. The water vapor adsorption properties and hydrothermal stability of the ethanol-treated samples were significantly enhanced. Additionally, a dual-atmosphere calcination process at 450 °C was established, showing results comparable to the conventional 550 °C process in terms of template removal. The sample, which combined dual-atmosphere calcination with ethanol treatment, demonstrated a significant increase in the water vapor adsorption capacity, achieving a 1.3-fold improvement compared to the untreated sample. These results provide a feasible reference for the application of MCM-41 in adsorption chillers.