Base Metal Catalyst for Indirect Hydrogenation of CO2.

We herein report a novel Mn-SNS-based catalyst, which is capable of performing indirect hydrogenation of CO2 to methanol via formylation. In this domain of CO2 hydrogenation, pincer ligands have shown a clear predominance. Our catalyst is based on the SNS-type tridentate ligand, which is quite stable and cheap as compared to the pincer type ligands. The catalyst can also be recycled effectively after the formylation reaction without any significant change in efficiency. Various amines including both primary and secondary amines worked well under the protocol to provide the desired formylated product in good yields. The formed formylated amines can also be reduced further at higher pressures of hydrogen. As a whole, we have developed a protocol that involves indirect CO2 hydrogenation to methanol that proceeds via formylation of amines.

Catalytic Acceptorless Dehydrogenation (CAD) of Secondary Benzylic Alcohols into Value-Added Ketones Using Pd(II)-NHC Complexes.

For the creation of adaptable carbonyl compounds in organic synthesis, the oxidation of alcohols is a crucial step. As a sustainable alternative to the harmful traditional oxidation processes, transition-metal catalysts have recently attracted a lot of interest in acceptorless dehydrogenation reactions of alcohols. Here, using well-defined, air-stable palladium(II)-NHC catalysts (A-F), we demonstrate an effective method for the catalytic acceptorless dehydrogenation (CAD) reaction of secondary benzylic alcohols to produce the corresponding ketones and molecular hydrogen (H2). Catalytic acceptorless dehydrogenation (CAD) has been successfully used to convert a variety of alcohols, including electron-rich/electron-poor aromatic secondary alcohols, heteroaromatic secondary alcohols, and aliphatic cyclic alcohols, into their corresponding value-added ketones while only releasing molecular hydrogen as a byproduct.

Natural-based coagulants/flocculants as sustainable market-valued products for industrial wastewater treatment: a review of recent developments.

Industrial wastewater is categorized as a voracious consumer of fresh water and a high-strength source of pollution. Coagulation-flocculation is a simple and cost-effective technique for removing organic/inorganic compounds and colloidal particles from industrial effluents. Despite the outstanding natural properties, biodegradability, and efficacy of natural coagulants/flocculants (NC/Fs) in industrial wastewater treatment, their significant potential to remediate such effluents is underappreciated, particularly in commercial scale applications. Most reviews on NC/Fs focused on the possible application of plant-based sources such as plant seeds, tannin, certain vegetables/fruit peels, and their lab-scale potential. Our review expands the scope by examining the feasibility of using natural materials from other sources for industrial effluent decontamination. By analyzing the latest data on NC/Fs, we identify the most promising preparation techniques for making these materials stable enough to compete with traditional options in the marketplace. An interesting presentation of the results of various recent studies has also been highlighted and discussed. Additionally, we highlight the recent success of using magnetic-natural coagulants/flocculants (M-NC/Fs) in treating diverse industrial effluents, and discuss the potential for reprocessing spent materials as a renewable resource. The review also offers different concepts for suggested large-scale treatment systems used by MN-CFs.

Design and Development of Novel Composites Containing Nickel Ferrites Supported on Activated Carbon Derived from Agricultural Wastes and Its Application in Water Remediation.

Recently, efficient decontamination of water and wastewater have attracted global attention due to the deficiency in the world's water sources. Herein, activated carbon (AC) derived from willow catkins (WCs) was successfully synthesized using chemical modification techniques and then loaded with different weight percentages of nickel ferrite nanocomposites (10, 25, 45, and 65 wt.%) via a one-step hydrothermal method. The morphology, chemical structure, and surface composition of the nickel ferrite supported on AC (NFAC) were analyzed by XRD, TEM, SEM, EDX, and FTIR spectroscopy. Textural properties (surface area) of the nanocomposites (NC) were investigated by using Brunauer-Emmett-Teller (BET) analysis. The prepared nanocomposites were tested on different dyes to form a system for water remediation and make this photocatalyst convenient to recycle. The photodegradation of rhodamine B dye was investigated by adjusting a variety of factors such as the amount of nickel in nanocomposites, the weight of photocatalyst, reaction time, and photocatalyst reusability. The 45NFAC photocatalyst exhibits excellent degradation efficiency toward rhodamine B dye, reaching 99.7% in 90 min under a simulated source of sunlight. To summarize, NFAC nanocomposites are potential photocatalysts for water environmental remediation because they are effective, reliable, and reusable.

Evaluating the efficacy of nanosized CuZnAl and CuZnZr mixed oxides for electrocatalytic CO2 reduction.

The increased awareness of carbon management has prompted the scientific community towards delivering sustainable catalytic technologies, preferably from CO2. Copper-based multifunctional catalysts are the most frequently used for thermal hydrogenation and electrocatalytic reduction of CO2 (CO2R) processes. To improve the understanding and efficacy of these materials for the CO2R reaction, Cu-Zn oxides combined with Al2O3 and ZrO2 were synthesized by the coprecipitation method and annealed at 500 °C, 600 °C, and 700 °C (i.e., Cu/ZnO/Al2O3-x and Cu/ZnO/ZrO2 systems-x, where x is the annealing temperature) to tune their multi-functionality. We demonstrate that the composition of Cu-Zn oxides and pretreatment temperature impact the electrocatalytic CO2R performance, where CuZnZr-600 and CuZnAl-700 materials are superior. Different characterization tools were employed to rationalize the results described in this work, which could provide a way to design an efficient catalytic system for the CO2R process.

C-CN bond formation: an overview of diverse strategies.

Nitrile or cyano compounds are an important part of structural motifs in dyes, agrochemicals, medicinal compounds, and electronic materials. Also, aryl nitrile is an important intermediate in the preparation of numerous compounds via transformations such as hydrolysis, hydration, reduction, cycloadditions, and nucleophilic additions. Such methods are beneficial for introducing sensitive functional groups in various positions in the multi-step synthesis of natural products and medicinal compounds. In the past decades, various cyanation methods have been reported in the vast arena of chemistry, which have made several building blocks accessible. Previously reported cyanation reviews, letters, and perspectives are written in parts. Thus, today a comprehensive review that will be able to guide readers through the vast pool of C-CN bond forming reactions via different approaches is obligatory. The present feature article depicts the various areas of cyanation methodologies that are based on the metal catalyst used, directed, non-directed, electrochemical, photochemical, asymmetric, and radical based approaches. This feature article will serve as a comprehensive tool to navigate the C-CN (cyanation) reactions across the vast area in synthetic chemistry.