Materials Today Catalysis最新文献

Electromagnetic induction heating currently attracts significant attention as a means to electrify catalytic processes and leverage a highly specific and localized energy supply. This Comment article features the application of this unconventional energy input for waste polymer conversion to fuel hydrocarbons.

Among the various molecular CO₂ reduction catalysts, the [Ni(cyclam)]²⁺ (Ni-{N₄}) complex with its earth-abundant metal center and macrocyclic ligand proved to be efficient for the selective electrochemical conversion of CO₂ to CO. In the present study we now connected the two Ni-cyclam units by using para- and meta-xylene as organic linkers attached to the amines of the macrocycle to form the p-{Ni₂} and m-{Ni₂} complexes, respectively, and test them as catalysts for the electrochemical CO₂ reduction reactions. Notably, the p-{Ni₂} complex demonstrates a higher faraday efficiency in the electrochemical reduction of CO₂ to CO compared to the m-{Ni₂} complex. This finding highlights the significant role played by the M-M distance in influencing this catalytic process.

Semiconductor photocatalyzed energy production and environment treatment have received a lot of attention. Mn–Cd–S solid solutions (Mn_xCd_1−xS) with tunable band structure, suitable redox capacity, and visible light response is recognized as one of the most promising photocatalysts for practical applications. However, low separation efficiency of photogenerated carriers and sluggish reaction kinetics restricts its photocatalytic activity. This review discusses the advantages and drawbacks of Mn_xCd_1−xS for photocatalysis in terms of electronic band structure and surveys the modification strategies of photocatalytic activity, including modulation of Mn/Cd ratio, morphology/structure regulation, defect engineering, construction of heterojunction, loading cocatalysts, and integration of multiple strategies. Then, the progress in photocatalytic water splitting to hydrogen, carbon dioxide reduction, and pollutant degradation using Mn_xCd_1−xS-based materials are summarized. Finally, it is concluded by outlining the challenges and opportunities for developing efficient photocatalysts based on Mn_xCd_1−xS.

The development of catalytic systems that selectively convert O₂ to water is required to progress fuel cell technology. As an alternative to platinum catalysts, derivatives of iron and cobalt porphyrin molecular catalysts provide one benchmark for catalyst design. However, the inclusion of these catalysts into homogeneous platforms remains a difficulty. Co-porphyrins have been studied as heterogeneous O₂ reduction catalysts; however, they have not been explored much in homogeneous systems. Moreover, they suffer from poor selectivity for the desired four-electron reduction of O₂ to H₂O. Herein, we present two cobalt-based β-fluorinated porphyrin complexes (CoTPF₈(OH)₂ and CoTPF₈(OH)₄) and demonstrate applicability as effective catalysts for the oxygen reduction reaction. Using rotating ring-disk electrochemistry, the catalysts, CoTPF₈(OH)₂ and CoTPF₈(OH)₄, showed maximum Faradaic efficiency for H₂O of 92 % and 97 %, respectively. DFT calculations suggest that the formation of a phlorin intermediate could occur before O₂ reduction and that a stronger H₂O₂ binding in the cobalt-based β-fluorinated porphyrin species compared to the unsubstituted parent compound, CoTP(OH)₂, was responsible for the observed experimental selectivity for H₂O. These results reveal that the β-fluorinated porphyrin catalyst serves as a novel platform for investigating molecular electrocatalytic reactions.

Two-dimensional (2D) materials, such as graphene, hexagonal boron nitride, 2D metal–organic frameworks, layered double hydroxides, transition metal dichalcogenides, and MXenes, have garnered significant attention in catalysis due to their exceptional properties and structures. Notably, recent studies have revealed the promising catalytic activity of MXene-based catalysts for many reactions, including hydrogen evolution, oxygen evolution, oxygen reduction, nitrogen reduction, carbon dioxide reduction, alcohol oxidation, hydrogenation, dehydrogenation, methanol conversion, dry reforming of methane, and CO oxidation. This review offers a summary of recent advances in the field, contextualizing the progress made. Additionally, it delves into existing challenges while presenting prospects for future developments in this domain.

This review delves into the underlying principles, advantages, challenges, and recent developments in photoelectrocatalysis (PEC) processes for wastewater treatment and green hydrogen production. PEC is an emerging technique that holds great promise for addressing two critical challenges simultaneously, namely, the degradation of industrial wastewater pollutants and the generation of clean energy in the form of hydrogen gas. In recent years, many studies have explored the use of photoanodes to harness solar energy for wastewater treatment. These photoanodes facilitate the breakdown of contaminants, while the cathode concurrently produces green hydrogen. The PEC enables the production of both clean water and hydrogen gas from industrial wastewater. This dual benefit makes it an attractive avenue for sustainable industrial wastewater treatment and clean energy generation. The PEC process capitalizes on the constructive interaction between electrochemical reactions and photocatalysis. Solar energy is efficiently converted into electron-hole pairs, which play a pivotal role in water-splitting reactions occurring at the electrode surfaces. Achieving the best performance involves scrutiny of various parameters, including catalyst loading, pH, light intensity, and electrolyte composition. The photoelectrocatalytic system shows commendable stability and durability during extended operation, reinforcing its practical applicability. This review provides a comprehensive overview of the PEC process, catalyst materials, optimization strategies, and driving efficiency. Considering the potential benefits and costs on a larger scale underscores the significance of photoelectrocatalytic hydrogen production in addressing environmental concerns and energy-related issues concurrently. Therefore, PEC is a promising pathway toward sustainable water treatment and clean energy, bridging the gap between environmental stewardship and technological advancement.

Ribbon-like coordination polymers (CP) represents a highly unexplored innovative class of metal-coordination network. Herein, we have developed a highly scalable and chemically robust (pH = 3–10 stable) ribbon-like CP [{Cu(Pim)(L)(H₂O)·H₂O}]_n (1) following a complete environment-friendly green synthesis route. Considering the presence of surface flanked labile coordinated water molecules and their appealing correlation with one-dimensional structural characteristics, such sort of ribbon-like CP was explored for the first time as excellent heterogeneous surface catalyst for largely unexplored three-component Hantzsch condensation for synthesis of different classes of dihydropyridine (DHP). Moreover, 1 is employed to synthesize bio-responsive drug ‘Ethidine’ (possessing high anti-oxidant and anticarcinogenic properties) characterized with Single Crystal X-ray Diffraction (SCXRD) analysis. Several DHP-based products are also analysed through in-depth SCXRD analysis. This report inaugurates the usage of a Cu(II) based ribbon-like CPs as heterogeneous surface catalyst following environmentally benign manner for synthesis of bioactive DHPs and Drugs.

The highly active and selective oxygen reduction reaction (ORR) is vital to promote the performance of advanced energy conversion systems, such as fuel cells and other electrochemical devices. Porous framework materials have the capability to combine the catalytic performance of catalytic active units with their porous characteristics, making them promising oxygen reduction catalysts. However, due to the difficulty in designing and synthesizing catalytic active units, the pore size modulation of framework materials is primarily achieved by altering the linkers. We herein report the design and synthesis of three cobalt-corrole-based porous organic polymers (Co-POP-1, Co-POP-2 and Co-POP-3) with different pore sizes, which were obtained by extending 5,15-meso substituents of Co corroles. Compared to Co-POP-1 and Co-POP-2, Co-POP-3 has the largest pore size. Benefiting from the enhanced mass transfer and the highly exposed active sites, Co-POP-3 displayed remarkably boosted activity for the selective four-electron/four-proton (4e⁻/4 H⁺) ORR with a half-wave potential of E_1/2 = 0.89 V versus reversible hydrogen electrode (RHE) in 0.1 M KOH solutions. This work not only presents a cobalt-corrole-based porous organic polymer catalyst with high ORR activity and selectivity but also provides a new strategy to moderate the pore size of porous framework materials.