A direct mechanochemical conversion of Pt-doped metal-organic framework-74 from doped metal oxides for CO oxidation

Pd/Ni-metal–organic framework-derived porous carbon nanosheets for efficient CO oxidation over a wide pH range

“…28 The CO oxidation mass activity of Pd 1 Sn 0.40 /TiO 2 -GO (~1500 mA/mg Pd ) was 6.07 folds greater than Pt 1 Sn 0.40 /TiO 2 -GO and 8.82 folds than MOFs are new classes of materials, and their carbonized derivatives have unique physiochemical properties of carbon and catalytic merits of metals (i.e., great surface areas, multiple unsaturated coordination sites, well-crystalline structures, abundant active sites, and interior/exterior cavities), which can provide interconnected channels for reactants during CO oxidation. [30][31][32][33][34][35][36][37][38][39][40][41][42] Meanwhile, MOFs with plentiful unsaturated coordination sites and open inner/outer cavities can accommodate Pd nanocrystals, which results in higher stability aggregation and maximize Pd utilization during CO oxidation. 38,[43][44][45][46][47] There are few reports on using MOFs and their derivatives as supports for Pd nanocrystals for thermal CO oxidation.…”

“…, high surface areas, multiple unsaturated coordination sites, well-crystalline structures, abundant active sites, and interior/exterior cavities), which can provide interconnected channels for reactants during CO oxidation. 30–42 Moreover, MOFs with numerous unsaturated coordination sites and open inner/outer cavities can accommodate Pd nanocrystals, which results in higher stability aggregation and maximize Pd utilization during CO oxidation. 38,43–47 There are a few reports on using MOFs and their derivatives as supports for Pd nanocrystals for thermal CO oxidation.…”

Pd-Nanoparticles Embedded Metal–Organic Framework-Derived Hierarchical Porous Carbon Nanosheets as Efficient Electrocatalysts for Carbon Monoxide Oxidation in Different Electrolytes

“…These results warrant the substantial enhancement in the CO oxidation activity and durability of Pd/ZIF-67/C, Pt/C, and Pd/C in HClO 4 , KOH, and NaHCO 3 electrolytes. This is plausibly attributed to synergism between the catalytic merits of Pd (i.e., favorable adsorption/activation of CO and O 2 dissociation besides H 2 oxidation at low potential) − , and exceptional properties of ZIF67/C (i.e., rich electron density and electrical conductivity). − ,− Meanwhile, the hierarchically porous carbon structure enhances diffusion of reactants and maximizes utilization of buried Pd/Co-N x . Notably, Co-N x species in ZIF-67/C act as anchoring sites for deposition of Pd nanoparticles to yield abundant Pd/Co-N x active sites, resulting in enhanced dispersion of Pd that is favorable for enhancement of CO oxidation.…”

“…Unlike other carbon-based supports, metal–organic frameworks (MOFs) are highly porous crystalline materials with extraordinarily high surface area to volume ratios, ordered crystalline structures, built-in active sites, modifiable surfaces, and abundant interconnected cavities that can accommodate guest species during electrocatalytic reactions. − Also, MOFs can be used as a template for porous carbon that can incorporate Pd or other metals through their centers with unsaturated coordination sites and stabilizes the metals against leaching or aggregation, as well as make the metal’s active sites more accessible, thus maximizing atom utilization during the CO oxidation reaction. MOF/C was used as a support for Pd and other metals for thermal but not electrochemical CO oxidation .…”

Insights into the Solid-State Synthesis of Defect-Rich Zr–UiO-66

“…While most MOFs are synthesized through solvothermal synthesis where an abundance of organic solvent is used, the green synthetic approach using a minimized amount of solvent is important to prevent irreversible environmental compacts. As an ecofriendly strategy, solid-state synthesis, in which the solid precursor can be converted to the specific MOFs without an abundance of solvent, has been attracting a lot of attention recently. − It has been reported that solid-state synthesis of MOFs has certain advantages in the rational synthesis of mixed-metal MOFs with controlled composition and the preparation of various biocomposite materials. , Up to now, a variety of advances have been made in the solid-state synthesis of MOFs, especially using a mechanochemical synthesis and an “accelerated aging” approach. − For example, the MOFs (e.g., ZIF-8, MOF-74, and HKUST-1) with simple metal nodes can be directly synthesized using simple metal compounds as the precursors. − However, the synthesis of MOFs (e.g., MOF-5 and UiO-66) with secondary structural units (SBUs) usually requires the construction of complex metal clusters prior to the formation of MOF crystals, which will lead to complex processes and expensive costs. , While previous studies have shown that the additives (e.g., organic modulator) could affect the types of products and facilitate the production of high-quality MOFs, − few works explore the mechanism involving additives. In general, the solid-state synthesis of MOFs is still in its infancy, and the exploration of this method will have positive impacts on the development of the MOF field.…”