Bifunctional Catalysts with Core–Shell Distributed ZrO₂ and Co Nanoparticles Derived from MOF-on-MOF Heterostructures for Economical One-Pot Tandem CO₂ Fixation

Abstract

The N-formylation of aryl amines with CO 2 is an emerging strategy to simultaneously reduce carbon emission and produce high-value formamides. Considering that aryl amines are usually produced from the hydrogenation of their corresponding nitroarenes in the chemical industry, the one-pot tandem hydrogenation−formylation of nitroarenes with CO 2 to formamides is obviously a much more economical but still unexploited strategy for efficient CO 2 fixation. Herein, we report the rational synthesis of bifunctional catalysts with core−shell distributed ZrO 2 and Co nanoparticles (NPs) from the controlled pyrolysis of a ZIF-67-on-UiO-66 heterostructure for this one-pot tandem reaction. To fabricate such MOF-on-MOF heterostructures, we develop a facile surfactant-assisted strategy to seed ZIF-8 nuclei on the UiO-66 surface, followed by the successful growth of a thickness-controlled ZIF-67 shell on the UIO-66 core. Based on further pyrolysis, the highly mesoporous derivants with core−shell distributed ZrO 2 and Co NPs can be obtained, of which the reductive Co and Lewis basic ZrO 2 can serve as highly active sites for the hydrogenation of nitroarenes and the N-formylation of aryl amines with CO 2 , respectively, due to their favorable electronic structures and good mass diffusion of reactants/intermediates. Impressively, the optimized core−shell catalyst achieves a much higher yield of N-(4methoxyphenyl)formamide (99.5%) than its ZrO 2 /C (0%), Co-NC (14.1%), and physically mixed counterparts (52.3%) for the one-pot tandem hydrogenation−formylation between 4-nitroanisole and CO 2 with good recyclability and a broad substrate scope, shedding light on the rational design of efficient bifunctional catalysts for this tandem CO 2 fixation reaction.

Silanol-Assisted High-Yield Nanofabrication of SnO2 Single Crystals with Highly Tunable and Ordered Mesoporosity

“…Thus, we anchored Pd NPs on 3DOm-SnO 2 (27) to prepare Pd/3DOm-SnO 2 (27) (Figures S45–S49 and Table S5). As shown in Figure S50, the Sn 3d XPS peaks of Pd/3DOm-SnO 2 (27) exhibit an obvious positive shift of ∼0.6 eV compared to those of 3DOm-SnO 2 (27), which indicates that electrons were transferred from SnO 2 to the Pd NPs, resulting in the accumulation of electrons on the Pd NPs to bring about some particular catalytic properties . Thus, we further investigated the catalytic performance of Pd/3DOm-SnO 2 (27) for the hydrogenation of 4-nitrophenylacetylene (NPA) to various high-value-added products (Figure S51).…”

Fluorinated Metal–Organic Frameworks with Dual-Functionalized Linkers to Enhance Photocatalytic H2 Evolution and High Water Adsorption

“…Significantly high atom utilization along with unique compositions and photocatalysis characteristics can describe single-atom catalysts. Nonetheless, the stability and catalytic activity of single atoms on appropriate substrates are still prerequisites of scientific studies. − Belonging to the most appropriate single-atom substrates and showing significant modularity, , metal–organic frameworks (MOFs) can be the most promising alternatives among others like zeolite, silica, and carbon. − MOFs are highly crystalline, structurally flexible, and adaptable, with adjustable internal structures, unsaturated coordination bonds, great specific surface areas, and stable porosity, all of which lead to their countless advantages. − …”

Facile construction of a sulfur vacancy defect-decorated CoSx@In2S3 core/shell heterojunction for efficient visible-light-driven photocatalytic hydrogen evolution

“…16 Furthermore, other compounds as metal and alloys have also been loaded on to ZIF-derived cores to form core/shell configurations. 17–19 Very recently, single-atom-phosphorus-vacancies-defects-decorated CoP hollow dodecahedrons were prepared through the phosphorylation and liquid corrosion of ZIF-67 dodecahedrons. After coating with the Cd 0.5 Zn 0.5 S nanodots shell, the core/shell heterojunctions presented a significant increase in photocatalytic hydrogen-production activity.…”