Predicting The Impact of a Formaldehyde Selective Metal-Organic Framework Material on Indoor Air Quality

Metal-Organic Framework (MOF) materials present a promising solution to enhance energy efficiency and improve indoor air quality (IAQ) in buildings. This research examines the ability of a MOF material to passively control formaldehyde – a harmful indoor pollutant – by integrating laboratory testing and predictive IAQ modeling.

Laboratory experiments used the microporous Al pyrazole carboxylate, denoted Al-3,5-PDA or MOF-303, that was previously identified as a highly efficient material to capture traces of formaldehyde in air without releasing it before 50°C. The formaldehyde adsorption performance was evaluated in a continuous 28-day small-scale chamber test, followed by a 7-day desorption phase. Tests were performed using an Al-3,5-PDA paper sheet at the formaldehyde concentration of 50 - 500 μg/m³ to assess the material’s adsorption performance. Evaluating of the long-term performance of MOF material in room-scale tests would provide valuable insight into their effectiveness in real-world scenarios. However, due to their high adsorption capacity and the significant cost of experimental specimens, it is too expensive to conduct long-term saturation tests or room-scale implementation. To compensate for the lack of the long-term test data, an IAQ simulation model was developed by integrating the tested adsorption capability via a multizone CONTAM software. This model used the parameters derived from short-term, small-scale tests to simulate large-scale, real-world applications. This model not only can enable more accurate forecasts of effectiveness under various scenarios, but also can reduce the cost to conduct extensive tests.

Simulations were carried out at room scale with interior walls coated with the Al-3,5-PDA. The simulation demonstrated a 47% short-term reduction of formaldehyde levels by coating 10 m² of wall surface in a 30 m³ room at 23 °C and 50% relative humidity. The results confirmed that Al-3,5-PDA’s high formaldehyde adsorption capacity, taking 150 days to reach saturation. These findings highlighted the potential of Al-3,5-PDA to effectively adsorb formaldehyde and reduce ventilation demands, contributing to energy savings and the improvement of IAQ in buildings. This study integrated short-term laboratory data into a scalable IAQ model, providing a cost-effective approach to predict performance of MOF materials in real-world building environments.