Heterometallic Metal‐Organic Frameworks for Enhanced Hydrogen Generation from Syngas: A Density Functional Theory Approach

Abstract Although methane poses environmental concerns, it is employed in hydrogen production processes such as steam‐methane reforming (SMR), which has an issue of by‐products released. Initiatives are being pursued to address CO and CO 2 emissions using carbon capture methods, with the goal of minimizing environmental harm while improving pure hydrogen generation from syngas. In this study, porous coordination network (PCN‐250) has been studied for its selective adsorption property towards CO, CO 2 and H 2 O as syngas mixture to obtain pure hydrogen. For this purpose, the trimetallic cluster node Fe 2 M (where Fe 2 represents the 3+ oxidation state and M is Cr(II), Mn(II), Fe(II), Co(II), Ni(II), and Zn(II)) has been considered. Fe(III) in combination with metal atoms like Cr(II), Co(II), or Ni(II) has been found to exhibit enhanced adsorption properties towards CO, CO 2 and H 2 O. The molecule with the strongest interaction was found to be H 2 O over Fe(III) 2 Zn(II) cluster and weakest interaction was found between H 2 and Fe(III) 2 Ni(II). Charge transfer, natural bond orbital (NBO) and spin density analyses reveal the electronic structural properties of this combination, leading to enhanced adsorption of CO and CO 2 .