In silico screening of metal-organic frameworks for CO2 photo-hydrogenation.

Abstract

Metal-organic frameworks (MOFs) are a promising class of materials that can be used as catalysts for photo-hydrogenation to convert CO2 to fuel by virtue of their nanoscale design featuring large surface area, abundant active metal sites, and ability to host dispersed co-catalysts. However, due to the vast combination of materials possible and general fragility of MOFs, experimental identification of catalytic materials is non-trivial. To aid in finding optimal catalytic candidates, we implement a multi-tiered high-throughput screening of 20 375 in silico MOFs for their porosity (≥4.5 Å), light absorption (1.7-3.5 eV), aqueous stability, and solvent removal stability. The 24 materials that passed screening were evaluated using density functional theory (DFT) applied to a proton-coupled electron transfer pathway for CO2 to CH4. Of eight thermodynamically favorable materials, three materials have been previously synthesized and the material precursors were analyzed for their material cost and life-cycle analysis, which revealed that Mg-MOF-74 had the lowest material cost ($15.11 per gram) and environmental impact. Five experimentally novel materials based on aluminum and zinc-based frameworks with pore diameters ranging from 4.7 to 21.6 Å, are presented for novel experimental realization.