Adsorption of gaseous formaldehyde on Y zeolites and on metal-organic frameworks

Formaldehyde is a known carcinogen and a major indoor air pollutant, which has led the authorities to regulate its levels in the air. To reduce indoor airborne concentrations, several strategies can be adopted, namely the reduction of emissions or the elimination of this pollutant by different depollution processes. Among them, adsorption on highly porous solid materials remains one of the most efficient strategy. This study aims to provide experimental data on formaldehyde adsorption capacity over different microporous materials at realistic levels (∼164 ppb), being representative of the performance of the investigated materials in a real environment. For that purpose, gaseous formaldehyde breakthrough experiments were performed under laboratory-controlled conditions over several porous solids: focusing on cation-exchanged zeolites and metal-organic frameworks (MOFs). These materials were fully characterized in terms of textural and structural properties. Cu-based MOFs acted as more promising HCHO adsorbents than zeolites, exhibiting at least one order of magnitude higher adsorption capacity under realistic indoor conditions. Among MOFs, SUM-102 (Strasbourg University Material) exhibited the highest surfacic adsorption capacity (0.52 μg HCHO m−2), yielding more than 1 kg HCHO adsorbed per m3sorbent being superior to the zeolite family by at least one order of magnitude.