Pillar-Layered Porous Metal–Organic Frameworks with Co₂N₂O₈ Clusters and Tetragonal Ligands for CO₂ Conversion

Abstract

Converting CO 2 to valuable chemicals and fuels is a viable method to establish a carbon-neutral energy cycle in the environment. Metal−organic frameworks (MOFs), characterized by dispersed active sites, high porosity, etc., have displayed a great application prospect in the electrochemical/chemical CO 2 reduction reaction (CO 2 RR) process. Herein, we proposed a one-step production to establish a series of pillar-layered porous MOFsfor preferential conversion of CO 2 via ligand adjustment and increase of active sites' density. According to single-crystal X-ray diffraction studies, [Co 2 (L)-(bimb)] n exhibits pillar-layered binuclear 3D frameworks with a 2,4,6-linked 3-nodes new topology structure, while [Co 4 (L) 2 (bidpe) 2 ] n displays pillar-layered tetranuclear interspersed networks with a 4,6-linked 2-nodes fsc topology structure through a ligand adjustment strategy. Meanwhile, the pillar-layered structure of the MOFs with abundant active sites is conducive to mass diffusion and benefits the conversion of CO 2 . MOFs 1−2 exhibit good electrocatalytic activity for CO 2 RR in 0.5 M KHCO 3 solution. Especially, the current density of MOF 2 generated at −0.90 V (vs. RHE) reaches −81.6 mA•cm −2 , which is 3.1 times higher than that under an Ar atmosphere. In addition, MOFs 1−2 can be used as a heterogeneous catalyst for chemical conversion of CO 2 . The results are expected to provide inspiration for rational design to develop stable and high-efficiency MOF-based electrocatalysts for CO 2 RR.

Robust High-performance Bifunctional Porous Cobalt MOF-Based Catalysts for Overall Water Splitting

“…Nevertheless, their high cost and scarcity limit their large-scale application. It is worthwhile to investigate the use of organic framework materials, including nonprecious metals, in the overall water splitting process. − Metal-organic framework (MOF) materials, being extensively studied catalysts, have garnered a lot of interest because of their abundant metal active sites and tunable framework structure. − For example, Chen et al synthesized a FeMn bimetallic MOF which exhibits good electrocatalytic performance for electrocatalytic total water decomposition . MOFs are currently used primarily to enhance electrocatalytic activity by their derivatives, such as various oxides, , phosphides, − sulfides, , or single-atom catalysts. , However, this can damage the original active sites in MOFs or even cause their structural collapse .…”