Catalytic Reaction Research Articles

Degradation of Emamectin Benzoate by Chemical Catalytic Reaction of Graphitic Carbon Nitride Based Nanoparticle

In recent years, metal–organic frameworks (MOFs), a new class of porous crystalline materials, have attracted great attention as a promising candidate for environmental remediation and catalytic applications. In this study, g-C3N4@ZIF-8 containing graphitic carbon nitride (g-C3N4) was synthesized to be used as a catalyst for the catalytic degradation of Emamectin benzoate pesticide with NaBH4. The synthesized gC3N4@ZIF-8 were characterized by Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy, Electron Dispersive X-ray and point of zero charge pH analysis. The degradation experiments of the synthetic pesticide were carried out in the presence of sodium borohydride (NaBH4) used as reducing agent and the degradation times of the pesticide were monitored in UV-Vis Spectrophotometer (UVVis). The catalytic activity of the prepared composite has been tested in aqueous medium at room temperature across a broad spectrum. Degradation experiments were conducted at room temperature in the presence of NaBH4, and the impact of various parameters such as pH, catalyst quantity, emamectin benzoate concentration, and NaBH4 amount has been thoroughly investigated in detail. g-C3N4@ZIF-8 nanocomposite showed superior NaBH4-induced chemical catalytic activity in degrading the toxic pollutant emamectin benzoate pesticide in a very short time. Kinetic parameters (k) for the degradation reactions were calculated and upon exposure to gC3N4@ZIF-8 nanoparticles, effective degradation of emamectin benzoate occurred in approximately 60 min. In the reduction reaction of emamectin benzoate pesticide with g-C3N4@ZIF-8, 70% degradation occurred within 60 min. This study provides insight into understanding nanoscale metal-organic frameworks (MOFs) in the removal of pesticides from wastewater.

Tumor-Targeted Catalytic Immunotherapy.

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Hybrid Metal-Organic Frameworks (MOFs) for Various Catalysis Applications.

Porous materials have been gaining popularity in catalysis applications, solving the current ecological challenges. Metal-organic frameworks (MOFs) are especially noteworthy for their high surface areas and customizable chemistry, giving them a wide range of potential applications in catalysis remediation. The review study delves into the various applications of MOFs in catalysis and provides a comprehensive summary. This review thoroughly explores MOF materials, specifically focusing on their diverse catalytic applications, including Lewis catalysis, oxidation, reduction, photocatalysis, and electrocatalysis. Also, this study emphasizes the significance of high-performance MOF materials, which possess adjustable properties and exceptional features, as a novel approach to tackling technological challenges across multiple sectors. MOFs make it an ideal candidate for catalytic reactions, as it enables efficient conversion rates and selectivity. Furthermore, the tunable properties of MOF make it possible to tailor its structure to suit specific catalytic requirements. This feature improves performance and reduces costs associated with traditional catalysts. In conclusion, MOF materials have revolutionized the field of catalysis and offer immense potential in solving various technological challenges across different industries.

Recent Advances in the Hydroxylation of Boronic Acids

AbstractHydroxylated compounds represent a significant and diverse class of substances in the field of chemistry. These compounds play critical roles in various chemical reactions and are essential components in numerous industrial applications. Recent years have witnessed remarkable advancements in the synthesis of hydroxylated compounds, especially those derived from boronic acids. The synthesis of hydroxylated compounds from boronic acids typically involves the utilization of various types of catalysts, which are essential for enhancing reaction rates and selectivity, including metal catalysts such as CuFe₂O₄, Cu@C₃N₄, AgNPs, and Ti0.97Ni0.3O1.97, as well as non‐metal catalysts like polycaprolactone (PCL), TFB‐BMTH COF materials, C70, and graphene oxide (GO). These catalytic reactions often require the addition of oxidants such as hydrogen peroxide (H₂O₂) or molecular oxygen, which serve as critical reagents in the hydroxylation process. In certain cases, organic bases act as electron donors to propel the reaction. Furthermore, some studies have reported oxidative hydroxylation reactions that are catalyst‐free.This review aims to summarize the recent advancements and breakthroughs in the synthesis of hydroxylated compounds from boronic acids, with a particular focus on research conducted from 2014 to 2024.

Structure of Ni(II) Inclusion Complex in Solid/Solution States and the Enhancement of Catalytic Behavior in Electrochemical Hydrogen Production.

In this article, we investigate the encapsulation of K2[Ni(maleonitriledithiolate)2] (1) within a host molecule, β-cyclodextrin (β-CD), via single-crystal X-ray analysis. An inclusion complex, K2{[Ni(maleonitriledithiolate)2]@(β-CD)2} (2), was constructed from 1 and two β-CDs. The anion guest Ni complex included a host cavity, constructed using two β-CDs, and the Ni atom of the anion was located between the two hydrophilic primary rims. Ultraviolet-visible absorption spectroscopy revealed that inclusion complex 2 exhibited a 2:1 (host:guest) stoichiometry in the solution, which is consistent with the result obtained from X-ray crystallography. The association of the host and guest occurred in two steps, and the association constants for the first and second steps were 1.1(7) × 104 and 1.8(5) × 104 mol-1 dm3, respectively. The catalytic behavior of 1 and 2 was investigated for electrochemical hydrogen production in the aqueous solution of an acetate buffer (pH = 4.72). During the catalytic reaction, inclusion complex 2 was observed to have a better catalytic reaction rate than 1. The study findings provide insights into the effects of the encapsulation of guest molecules within host structures.

Kinetic Profiling of Oxidoreductase-Mimicking Nanozymes: Impact of Multiple Activities, Chemical Transformations, and Colloidal Stability.

In contrast to homogeneous enzyme catalysis, nanozymes are nanosized heterogeneous catalysts that perform reactions on a rigid surface. This fundamental difference between enzymes and nanozymes is often overlooked in kinetic studies and practical applications. In this article, using 14 nanozymes of various compositions (core@shell, metal-organic frameworks, metal, and metal oxide nanoparticles), we systematically demonstrate that nontypical features of nanozymes, such as multiple catalytic activities, chemical transformations, and aggregation, need to be considered in nanozyme catalysis. Ignoring these features results in the inaccurate quantification of catalytic activity. Neglecting the multiple activities led to a six-time underestimation of Mn2O3 oxidation activity and mischaracterization of this material as a low-active peroxidase-mimicking nanozyme. Additionally, overlooking chemical stability during catalytic reactions led to the reporting of high peroxidase-mimicking activity for Au@Ag nanoparticles, which, in reality, exhibited no intrinsic activity and oxidized the substrate through the leakage of Ag+ ions. Ignoring the chemical stability of Au@Prussian Blue nanoparticles may lead to more than four times overestimation of peroxidase-mimicking activity after just 24 h of storage. Finally, disregarding the colloidal stability of nanozymes led to a five-time inaccuracy in catalytic activity. These findings underscore the necessity of optimizing procedures to account for these factors in nanozyme kinetic measurements, which will in turn ensure more reliable biosensors and the success of other practical applications.

Pt Nanocatalysts Modified with Carbon Dots as Nonmetallic Promoters for Enhanced Selective Hydrogenation Performance

AbstractConstructing nonmetal promoter‐decorated Pt‐based catalysts is a promising strategy for enhancing selective hydrogenation performance. In this study, a set of carbon dots (CDs)‐modified Pt/SBA‐15 nanocatalysts were synthesized using atomic layer deposition (ALD) and impregnation techniques. The catalysts were characterized using various techniques, including TEM, ICP‐MS, N2 adsorption–desorption isotherms, XRD, XPS, H2−TPD, H–D exchange, CO‐DRIFTS, and so forth. The catalytic performance of the CDs‐Pt/SBA‐15 catalysts was evaluated by the selective hydrogenation reaction of cinnamaldehyde (CAL) to cinnamyl alcohol (COL). The results indicate that there is electron transfer between the CDs and Pt, and the addition of CDs can improve the hydrogen spillover effect, both of which significantly influence the selective catalytic hydrogenation performance of the CDs‐Pt/SBA‐15 catalysts. Among the tested catalysts, 0.44CDs‐Pt/SBA‐15 demonstrated the highest catalytic performance, with conversion and selectivity 2.8 times and 2.2 times higher, respectively, than Pt/SBA‐15. This study provides a new perspective on designing and preparing highly efficient nonmetallic promoter‐modified Pt‐based nanocatalysts and has significant implications for their application in catalytic reactions.

Suspending Light-Absorbing Nanoparticles in Silica Aerogel Enables Numerous Superblacks.

Current strategies for constructing sparse nanostructures for fabricating superblacks are only suitable for a few light-absorbing materials, severely limiting their applications. Herein, ultra-low reflective silica aerogels with ultra-high light transparency are used as solid smokes to individually or simultaneously suspend at least 100 species of light-absorbing nanoparticles with a volume fraction as low as 0.005%, for creating > 100 superblacks in practice and one billion superblacks in theory if taken permutation and combination among these 0D, 1D, or 2D nanoparticles into account. Depending on the composition of suspended nanoparticles and the structure of solid smoke, the resulting mechanically robust superblacks with supplementary properties including magnetism, full-spectrum absorption, high thermal stability, and excellent mechanical strength, are first observed. The wide choice of metallic or semiconductive LNs allows as-made superblacks to glitter in different catalytic reactions, and the resulting superblacks have been on-demand modified for endowing the self-cleaning performance in some contaminable environments. Benefiting from the superblack feature and porous network, these superblack monoliths have shown high-efficiency solar-heat conversion in some emerging light harvesting and managing fields. This powerful synthetic strategy for superblacks is expected to inspire researchers to conduct in-depth investigations on super-black optics, functional materials, etc.

Commercial Silica Materials Functionalized with a Versatile Organocatalyst for the Catalysis Of Acylation Reactions in Liquid Media.

Silica materials, natural and synthetic variants, represent a promising material for the application in heterogeneous organocatalysis due to their readily modifiable surface and chemical inertness. To achieve high catalyst loadings, usually, porous carriers with high surface areas are used, such as silica monoliths or spherical particles for packed bed reactors. While these commercial materials were shown to be efficient supports, their synthesis is elaborate, and thus less complex and cheaper alternatives are of interest, especially considering scaling up for potential applications. In this work, two commercial silica materials functionalized with the organocatalyst 4-(dimethylamino)pyridine (DMAP) were used in catalytic acylation reactions: a mesoporous silica gel (Siliabond-DMAP) and non-porous silica nanoparticles (Ludox). While both were successfully used in the acylation of phenylethanol, the latter required significantly longer reaction times, presumably due to the lack of mesopores and the associated spatial confinement, as well as agglomeration that limits the active amount of catalyst. Furthermore, we find that the influence of the linker molecule is negligible, since for two different linker motifs the reaction yields and activation energy remain largely similar. Lastly, as main result the commercial material Siliabond-DMAP, despite the non-uniform particles, were employed in a flow setup, thus demonstrating the potential as support material for application in heterogeneous organocatalysis.

Spatial resolution of a velocity-selected ion imaging microscope for surface reaction kinetics mapping.

Experimental validation of complex microkinetic models derived from quantum chemistry is crucial for the advancement of bottom-up approaches to heterogeneous catalysis. State-of-the-art velocity-resolved kinetics experiments have made tremendous progress in this arena but integrate reactivity over centimeter-scale single-crystal catalytic surfaces even when complex spatial phenomena may perturb the kinetic results. We report a new design, optimization, and analysis of an ion imaging microscope that can collect spatially resolved kinetic data from a catalytic surface. In its simplest configuration, gaseous reaction products are ionized by a laser line or sheet above a catalytic surface. The resulting ions are extracted and strongly lensed to an intermediate velocity-mapped plane where a pinhole of radius r only transmits ions produced from reaction products with desorption velocities within a narrow solid angle centered on the surface normal. Transmitted ions re-expand through an electrostatic zoom lens to form a spatial image of the initial reaction product distribution with reduced blur from desorption velocity components parallel to the surface. The ion hits that define the magnified and deblurred spatial image can be used to determine spatiotemporal flux and speed-distributions of gas leaving the catalyst surface. Electrostatic trajectory simulations are performed and verify that transmission is ∝r2/TSurface. However, calculated global point spread functions acting on the magnified image have a width that is ∝r and largely independent of TSurface. Thus, velocity-filtered ion imaging microscopy can deliver a consistent resolution as the TSurface is varied, which is a great advantage because many catalytic reactions require elevated temperatures.

Effect of alkaline-acid treatment on the physicochemical properties of ferrierite zeolite with application in the catalytic cracking reactions of n-hexane and UHMWPE

Effect of alkaline-acid treatment on the physicochemical properties of ferrierite zeolite with application in the catalytic cracking reactions of n-hexane and UHMWPE

A Review on Biomass-Derived Carbon Quantum Dots: Emerging Catalysts for Hydrogenation Catalysis.

The circular economy and the depletion of Earth's resources highlight the need to transform waste into value-added emerging materials like carbon quantum dots (CQDs), which show great promise in energy storage, catalysis, and other applications. The production of catalytically active CQDs from biomass garners significant attention due to their unique advantages, such as ease of availability, natural abundance, renewability, low cost, and environmental friendliness. This review addresses the synthesis of CQDs from biomass, the factors influencing their properties and performance, and their diverse applications in catalytic hydrogenation reactions, selective reduction of nitroaromatic compounds, and azo dyes. Recent studies demonstrate that biomass-derived CQDs exhibit significantly improved catalytic activity, selectivity, and stability, effectively addressing the long-standing challenges of low activity and poor stability in catalysts derived from conventional sources.

Enantioselective Cycloaddition of in Situ Formed aza-Dienes and Vinyl Diazo Compounds for the Synthesis of Optically Enriched and Diazo Containing Tetrahydropyridazine.

A copper catalyzed enantioselective formal aza-Diels-Alder reaction of in situ formed 1,2-diaza-1,3-dienes from α-halohydrazones and vinyl diazo compounds was described. The protocol provides a variety of optically enriched diazo-containing tetrahydropyridazines in moderate yields and with up to excellent enantioselectivities. The present methodologies utilize chiral oxazolines as the chiral ligands for asymmetric catalysis and feature mild reaction conditions, readily available substrates, and broad substrate scope.

Characterizations of Some Selected Clay Types for Cost Effective Wastewater Treatments

Water pollution poses a significant challenge to water consumption, particularly in relation to drinking purposes. Various factors such as industrial discharge, improper waste management, waste build-up, and natural activities contribute to the contamination of water bodies. Adequate water treatment plays a crucial role in the preservation of water quality and compliance with environmental regulations. The treatment process typically involves the application of physical, chemical, and biological techniques, with a common reliance on chemical substances and intricate systems. Recent studies have increasingly explored the utilization of cost-efficient natural materials for water treatment, highlighting benefits like affordability, user-friendliness, health advantages, and widespread availability. This particular investigation aimed to assess the suitability of selected natural substances for the treatment of wastewater, focusing primarily on methods like adsorption, absorption, and filtration. A number of earth materials, notably three distinct types of clays prevalent in Sri Lanka, were singled out for examination. The findings unveiled that these clays predominantly consist of over 75% iron in their mineral composition, with certain samples displaying finer particles to enhance porosity and permeability. These raw materials exhibit potential for the fabrication of wastewater treatment systems intended for the elimination of suspended particles, dissolved solids, heavy metals, pathogens, oils, and toxic compounds. Their distinct chemical properties render them appropriate for catalytic reactions and advanced chemical processes

Two‐Dimensional Catalysts: From Model to Reality

AbstractTwo‐dimensional (2D) materials have been utilized broadly in kinds of catalytic reactions due to their fully exposed active sites and special electronic structure. Compared with real catalysts, which are usually bulk or particle, 2D materials have more well‐defined structures. With easily identified structure‐modulated engineering, 2D materials become ideal models to figure out the catalytic structure‐function relations, which is helpful for the precise design of catalysts. In this review, the unique function of 2D materials was summarized from model study to reality catalysis and application. It includes several typical 2D materials, such as graphene, transition metal dichalcogenides, metal, and metal (hydr)oxide materials. We introduced the structural characteristics of 2D materials and their advantages in model researches. It emphatically summarized how 2D materials serve as models to explore the structure‐activity relationship by combining theoretical calculations and surface research. The opportunities of 2D materials and the challenges for fundamentals and applications they facing are also addressed. This review provides a reference for the design of catalyst structure and composition, and could inspire the realization of two‐dimensional materials from model study to reality application in industry.

Recent Advances in Photoredox/Chromium dual‐Catalyzed Carbonyl Addition Reactions: A Review

The chromium‐catalysed Nozaki‐Hiyama‐Kishi (NHK) reaction is a very dependable technique for alcohol synthesis and is extensively used in the complete synthesis of natural compounds. The majority of these reactions occur via a reductive‐radical‐polar crossover (RRPCO) mechanism, which is crucial for the transformation of reactive radical intermediates. The production of radicals using photoinduced catalytic reactions is now among the most effective approaches. The photoinduced chromium‐catalysed addition reaction to carbonyl compounds is an effective technique for alcohol synthesis that integrates the benefits of photocatalysis with chromium catalysis. Photocatalysis significantly enhances the diversity of radical production, hence broadening the substrate scope in the chromium‐catalysed NHK reaction. This paper primarily examines the photoredox chromium dual‐catalysed carbonyl addition process for alcohol synthesis, including numerous methods for radical generation.

N-Doped Carbon-Incorporated Cobalt-Iron Mixed-Metal Phosphide Nanoboxes as Efficient Bifunctional Catalysts for Overall Water Splitting.

Optimizing the composition and structure of nanocatalysts is an efficient approach to achieving the top electrocatalytic performance. However, the construction of hollow nanocomposites composed of metal phosphides and highly conductive carbon to promote the electrocatalytic performance of metal phosphide-based catalysts is rarely reported. Herein, a CoFeP/C nanobox nanocomposite consisting of Co-Fe mixed-metal phosphides and N-doped carbon was successfully fabricated through an ion-exchange phosphidation strategy derived from ZIF-67 nanocubes. Benefiting from the synergistic effects between multiple components and the unique hollow structure, CoFeP/C nanoboxes can catalyze the alkaline oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with high activity and stability. Furthermore, in the construction of an alkaline water electrolyzer using CoFeP/C nanoboxes as both OER and HER catalysts, they were capable of efficiently splitting water with a current density of 10 mA cm-2 achieved by applying only 1.62 V of cell voltage and exhibited outstanding durability. Density functional theory calculations demonstrate that synergistic effects among multiple components in CoFeP/C nanoboxes can lower the hydrogen adsorption free energy of the HER and OER energy barrier of the rate-determining step, thus promoting the catalytic reactions. The design and synthesis of CoFeP/C nanoboxes highlight the importance of the composition and structural characteristics in achieving high-performance water electrolysis.

Two-Dimensional Catalysts: From Model to Reality.

Two-dimensional (2D) materials have been utilized broadly in kinds of catalytic reactions due to their fully exposed active sites and special electronic structure. Compared with real catalysts, which are usually bulk or particle, 2D materials have more well-defined structures. With easily identified structure-modulated engineering, 2D materials become ideal models to figure out the catalytic structure-function relations, which is helpful for the precise design of catalysts. In this review, the unique function of 2D materials was summarized from model study to reality catalysis and application. It includes several typical 2D materials, such as graphene, transition metal dichalcogenides, metal, and metal (hydr)oxide materials. We introduced the structural characteristics of 2D materials and their advantages in model researches. It emphatically summarized how 2D materials serve as models to explore the structure-activity relationship by combining theoretical calculations and surface research. The opportunities of 2D materials and the challenges for fundamentals and applications they facing are also addressed. This review provides a reference for the design of catalyst structure and composition, and could inspire the realization of two-dimensional materials from model study to reality application in industry.

Self-organization of Janus particles: Impact of hydrodynamic interactions in substrate consumption for structure formation.

We show that the formation of active matter structures requires them to modify their surroundings by creating inhomogeneities such as concentration gradients and fluid flow around the structure constituents. This modification is crucial for the stability of the ordered structures. We examine the formation of catalytic Janus particle aggregates at low volumetric fractions in the presence of hydrodynamic interactions (HIs). Our study shows the types of structures formed for various values of the kinetic constant of the catalytic reaction. The presence of HI causes the aggregate particles to have higher mobility than in the case of the absence of such interactions, which is reflected in the behavior of the pair distribution function. Although HI decreases energy conversion efficiency, they play a significant role in the formation of complex structures found in nature. Self-organization of these structures is driven by direct feedback loops between structure formation and the surrounding medium. As the structures alter the medium by consuming substrate and perturbing fluid flow, the substrate concentration, in turn, dictates the kinetics and configuration of the structures.

Recent Advances in Direct Amidation via Organocatalysis

The formation of amide bonds is essential for a wide range of applications in biological and organic systems, including proteins, pesticides, polymers, and pharmaceuticals. Moreover, it plays a critical role in the synthesis of numerous bioactive compounds with anticancer, antibacterial, and antifungal properties. Due to the limitations of conventional coupling reagents for amide synthesis, there is a growing demand for environmentally sustainable methodologies, particularly the direct formation of amides from carboxylic acids and amines. Over recent years, we have developed several catalytic reactions based on organocatalysis, advancing sustainable synthetic methods in both organic and medicinal chemistry. This review comprehensively discusses catalytic amidation reactions published up to January 2024, focusing on both organocatalysis and boron‐based catalysis for the direct condensation of carboxylic acids and amines. Additionally, it highlights our recent contributions to sustainable amidation protocols, which are progressively replacing traditional catalytic approaches in modern synthetic chemistry.