Optimised room temperature, water-based synthesis of CPO-27-M metal–organic frameworks with high space-time yields

Abstract

The exceptional porosity of Metal–Organic Frameworks (MOFs) could be harnessed for countless practical applications. However, one of the challenges currently precluding the industrial exploitation of these materials is a lack of green methods for their synthesis. Since green synthetic methods obviate the use of organic solvents, they are expected to reduce the production costs, safety hazards and environmental impact typically associated with MOF fabrication. Herein we describe the stepwise optimisation of reaction parameters (pH, reagent concentrations and reaction time) for the room temperature, water-based synthesis of several members of the CPO-27/MOF-74-M series of MOFs, including ones made from Mg(II), Ni(II), Co(II) and Zn(II) ions. Using this method, we built MOFs with excellent BET surface areas and unprecedented Space-Time Yields (STYs). Employing this approach, we have synthesised CPO-27-M MOFs with record BET surface areas, including 1279 m² g⁻¹ (CPO-27-Zn), 1351 m² g⁻¹ (CPO-27-Ni), 1572 m² g⁻¹ (CPO-27-Co), and 1603 m² g⁻¹ (CPO-27-Mg). We anticipate that our method could be applied to produce CPO-27-Ni, -Mg, -Co and -Zn with STYs of 44 kg m⁻³ per day, 191 kg m⁻³ per day, 1462 kg m⁻³ per day and a record 18 720 kg m⁻³ per day, respectively.