Proof of concept for CUK family metal-organic frameworks as environmentally-friendly adsorbents for benzene vapor. (15th September 2021) - Anand, Bhaskar
Abstract: The utility of metal-organic frameworks (MOFs) such as the CUK family (CUK – Cambridge University–KRICT) has been explored intensively for adsorption/separation of airborne volatile organic compounds (VOCs). In this article, three M-CUK analogs (M = Mg, Co, or Ni) were synthesized hydrothermally under similar conditions to assess the effects of their isostructural properties and metal centers on adsorption of benzene vapor (0.05–1 Pa). A list of performance metrics (e.g., breakthrough volume (BTV) and partition coefficient (PC)) were used to assess the role of the metal type (in M-CUK-1s) in the adsorption of VOCs. Specifically, Co-CUK-1 (average pore size of 8.98 nm) showed 2–3 times greater performance (e.g., in terms of 10% BTV (2012 L atm g −1 ) and PC (6 mol kg −1 Pa −1 )) over other analogs when exposed up to 0.05 Pa benzene vapor. The superiority of mesoporous Co-CUK-1 (e.g., enhanced adsorption diffusion mechanism through favorable metal-π and π- π interactions) can be attributed to the presence of cobalt metal centers (e.g., in reference to Mg- or Ni-CUK-1). Graphical abstract: Image 1 Highlights: The utility of M-CUK-1 (M = Mg, Co, and Ni) is assessed for benzene uptake. Pore textural properties and π-π interactions played a vital role in adsorption of benzene. Co-CUK-1 outperformed other studied CUK MOFs in uptake of benzene. The kinetic rate constants exhibited a linear relationship with benzene vapor level.