Nitrogen-doped graphene-activated metallic nanoparticle-incorporated ordered mesoporous carbon nanocomposites for the hydrogenation of nitroarenes

Electrochemical reduction of CO2 and N2 to synthesize urea on metal-nitrogen-doped carbon catalysts: a theoretical study

Fossil fuels have been increasingly consumed since the industrial revolution, causing rapid increases in carbon dioxide emissions and disrupting the global carbon cycle. With increasing attention being paid to the harmful effects of carbon dioxide as a "greenhouse gas", its use as a feedstock for basic chemical production is an attractive topic. Nature benefits humans through "crops brought by thunderstorms". Combining these two methods to produce urea containing nitrogen is the focus of this paper. In this paper, a series of catalysts supported on the substituted corrole substrates in the form of a double transition metal are investigated by DFT calculations. The best catalyst was selected and combined with carbon and nitrogen reduction to further explore the catalytic performance of urea synthesis. Based on this study, it was found that the synergistic catalytic strategy of double active sites had broad prospects in urea synthesis, and could also provide new development strategies for the design of other efficient molecular catalysts.

Recent Advances on Heteroatom-Doped Porous Carbon/Metal Materials: Fascinating Heterogeneous Catalysts for Organic Transformations

Design and preparation of low-cost, effective, and novel catalysts are important topics in the field of heterogeneous catalysis from academic and industrial perspectives. Recently, heteroatom-doped porous carbon/metal materials have received significant attention as promising catalysts in divergent organic reactions. Incorporation of heteroatom into the carbon framework can tailor the properties of carbon, providing suitable interaction between support and metal, resulting in superior catalytic performance compared with those of traditional pure carbon/metal catalytic systems. In this review, we try to underscore the recent advances in the design, preparation, and application of heteroatom-doped porous carbon/metal catalysts towards various organic transformations.

H2 Activation with Co Nanoparticles Encapsulated in N-Doped Carbon Nanotubes for Green Synthesis of Benzimidazoles

Co nanoparticles (NPs) encapsulated in N-doped carbon nanotubes (Co@NC₉₀₀ ) are systematically investigated as a potential alternative to precious Pt-group catalysts for hydrogenative heterocyclization reactions. Co@NC₉₀₀ can efficiently catalyze hydrogenative coupling of 2-nitroaniline to benzaldehyde for synthesis of 2-phenyl-1H-benzo[d]imidazole with >99 % yield at ambient temperature in one step. The robust Co@NC₉₀₀ catalyst can be easily recovered by an external magnetic field after the reaction and readily recycled for at least six times without any evident decrease in activity. Kinetic experiments indicate that Co@NC₉₀₀ -promoted hydrogenation is the rate-determining step with a total apparent activation energy of 41±1 kJ mol^-1 . Theoretical investigations further reveal that Co@NC₉₀₀ can activate both H₂ and the nitro group of 2-nitroaniline. The observed energy barrier for H₂ dissociation is only 2.70 eV in the rate-determining step, owing to the presence of confined Co NPs in Co@NC₉₀₀ . Potential industrial application of the earth-abundant and non-noble transition metal catalysts is also explored for green and efficient synthesis of heterocyclic compounds.

Carbon-Based Materials for the Development of Highly Dispersed Metal Catalysts: Towards Highly Performant Catalysts for Fine Chemical Synthesis

Single-atom catalysts (SACs), consisting of metals atomically dispersed on a support, are considered as advanced materials bridging homogeneous and heterogeneous catalysis, representing the catalysis at the limit. The enhanced performance of these catalysts is due to the combination of distinct factors such as well-defined active sites, comprising metal single atoms in different coordination environments also varying its valence state and strongly interacting with the support, in this case porous carbons, maximizing then the metal efficiency in comparison with other metal surfaces consisting of metal clusters and/or metal nanoparticles. The purpose of this review is to summarize the most recent advances in terms of both synthetic strategies of producing porous carbon-derived SACs but also its application to green synthesis of highly valuable compounds, an area in which the homogeneous catalysts are classically used. Porous carbon-derived SACs emerge as a type of new and eco-friendly catalysts with great potential. Different types of carbon forms, such as multi-wall carbon nanotubes (MWCNTs), graphene and graphitic carbon nitride or even others porous carbons derived from Metal–Organic-Frameworks (MOFs) are recognized. Although it represents an area of expansion, experimentally and theoretically, much more future efforts are needed to explore them in green fine chemical synthesis.

Iron Pyrite Nanocrystals: A Potential Catalyst for Selective Transfer Hydrogenation of Functionalized Nitroarenes

We report a solution-based synthetic method to produce shape-tunable iron pyrite (FeS2) nanocrystals using iron oxy-hydroxide (β-FeOOH) as a precursor and their application for selective reduction of functionalized nitroarenes to aniline derivatives with formic acid-triethylamine (HCOOH-Et3N) as a hydrogen donor system.

Reduction of Nitro Compounds Using 3d-Non-Noble Metal Catalysts

The reduction of nitro compounds to the corresponding amines is one of the most utilized catalytic processes in the fine and bulk chemical industry. The latest development of catalysts with cheap metals like Fe, Co, Ni, and Cu has led to their tremendous achievements over the last years prompting their greater application as "standard" catalysts. In this review, we will comprehensively discuss the use of homogeneous and heterogeneous catalysts based on non-noble 3d-metals for the reduction of nitro compounds using various reductants. The different systems will be revised considering both the catalytic performances and synthetic aspects highlighting also their advantages and disadvantages.