Comparison of removal ability of indoor formaldehyde over different materials functionalized with various amine groups

In this study, a mesoporous material (MCM-41), crystalline microporous zeolite (HY), and amorphous silica (XPO-2412) were functionalized with three kinds of amine groups, namely 3-aminopropyltriethoxysilane (APTES), N(β-aminoethyl) γ-aminopropylmethyl dimethoxysilane (AEAPMDMS), and N¹-(3-(trimethoxysilyl)-propyl) diethylenetriamine (TMSPDETA) and their performances for formaldehyde adsorption evaluated. BET, XRD, and elemental analysis were used to evaluate structural and surface characteristics of the adsorbents. Due to its large specific surface area, the adsorption efficiency of MCM-41 increased with the amount of amine groups (MCM-41/APTES<MCM-41/AEAPMDMS<MCM-41/TMSPDETA) functionalized to its surface; whereas AEAPMDMS was the best amine group for HY and XPO-2412 as TMSPDETA reduced the surface area to a great extent. The order of formaldehyde removal efficiency was shown to be MCM-41/TMSPDETA>XPO-2412/AEAPMDMS>HY/AEAPMDMS. The adsorption efficiency was the highest at 30°C, while decreasing rapidly above 30°C, suggesting an optimum temperature for interaction between the amine groups and formaldehyde. Given the results of this study, amine functionalized MCM-41 is believed to have great potential as an adsorbent for removing indoor formaldehyde at room temperature.