Carbon dioxide electroreduction over imidazolate ligands coordinated with Zn(II) center in ZIFs

Heterogeneous Single‐Atom Catalysts for Electrochemical CO2 Reduction Reaction

“…Thus, MOFs with different metal nodes are promising and have been studied as catalysts for CO 2 RR. [ 163–165 ] Recently, converting the organic ligands of MOFs into N‐doped carbon materials by heat treatment not only maintains the merits of MOFs but also improves the electrical conductivity of the catalysts. [ 166,167 ] Either metal‐containing nodes/linkers or absorbed metal ions in MOFs can turn into atomically dispersed M‐N x sites during the heat treatment.…”

Engineering Metal–Organic Frameworks for the Electrochemical Reduction of CO2: A Minireview

“…Jiang et al. further identified the imidazolate ligands that were coordinated to the zinc(II) center in the ZIFs as the catalytic sites for CO 2 ER with the help of in situ X‐ray absorption spectroscopy (XAS) measurements and DFT calculations . They investigated a range of ZIFs that exhibited the same sodalite topology but with different organic ligands, including ZIF‐8, ZIF‐108, ZIF‐7, and substituted imidazolate material SIM‐1, for the CO 2 ER in aqueous electrolyte.…”

The Origin of the Electrocatalytic Activity for CO2 Reduction Associated with Metal‐Organic Frameworks

“…By contrast, in situ X-ray absorption spectroscopy measurements and density-functional theory calculations undertaken by Jiang et al suggested that the oxidation state of Zn centers in ZIFs remainu nchanged under catalytic turnover conditions. [11] These contradictoryresultsprovideconfusion as to the stability of this MOF.…”

“…According to the SEM images, the as-synthesized Co-ZIF andZ n-ZIF MOFs both have well-defined rhombic dodecahedral shapes.H owever,t he morphologies of Cu-BTC and Zn-BTC are less well defined, which is consistent with literature reports. [6,7,10,11,13] The control of MOF morphology is not straightforward without using surfactantso rt emplates,b ut since this feature should not significantly influence electrochemicals tability,i tw as not deliberately controlled in this study.T he powder XRD patterns of all four MOFs of interesti n this study match well with their simulated patterns, thereby confirming good crystallinity and purity. Anodic stripping voltammetry is ah ighlys ensitive electrochemicalt echnique for the quantitative determination of trace metal ions in solution.…”

“…To probe the mechanistic details,a nodics tripping voltammetry was appliedi nsitu to monitor the extent of decomposition of the MOFs that occurred duringt he course of reductivee lectrolysis.S ince MOFs are electricali nsulators, they are often mixed with carbon black to improve their electrical conductivity when preparing electrocatalysti nks used for electrode modification. [10,11] To mimic this commonly reported experimental condition, ak nown amount of the MOFs was mixed with carbonb lack for the electrode modification. The introduction of carbon black increases the number of three-phase junctions and hence is expected to accelerate the decomposition of MOFs.Again, ap otentialo fÀ1.4Vwas applied.…”