Bifunctional Heterogeneous Catalyst Research Articles

Mixed Metal Oxide Derived from Polyoxometalate-Based Metal–Organic Framework as a Bi-Functional Heterogeneous Catalyst for Wastewater Treatment

The efficient removal of dyes and Cr(VI) from wastewater is imperative. Therefore, a mixed metal oxide CuMoV(450) derived from a polyoxometalate-based metal–organic framework (POMOF) [Cu(2,2′-bipy)][Cu(2,2′-bipy)2]2[PMo8V6O42]•2H2O (CuMoV) was synthesized by calcination, fully characterized by XRD, XPS, FT-IR, and SEM methods, and explored for the heterogeneous catalytic degradation of methylene blue (MB) dye and the catalytic reduction of Cr(VI) in aqueous media over NaBH4 under mild conditions. The removal rates for MB and Cr(VI) were 95.9% (30 min) and 96.5% (2.0 min), respectively. The pseudo-first-order rate constants of MB degradation and Cr(VI) reduction were 0.093 min−1 and 1.536 min−1, respectively. The highly catalytic reusability of CuMoV(450) was confirmed by the recycling experiments. Moreover, the possible mechanisms of MB degradation and Cr(VI) reduction were proposed. The catalytic activities of CuMoV(450) were much better than those of its parent compound CuMoV, proving that POMOFs were good candidates for the preparation of mixed metal oxides with excellent catalytic performances. This work not only indicates that CuMoV(450) has the potential to be a satisfied catalyst for wastewater remediation via catalytic degradation and reduction, but also gives a clue to synthesize mixed metal oxides with excellent catalytic properties by the calcination of POMOFs.

One-pot conversion of non-edible oil into sustainable biodiesel using novel bifunctional heterogeneous catalyst

This study aims to produce biodiesel from indigenous non-edible feedstock of wild olive seed oil using novel bifunctional xK2O/ZrO2-Bi2O3 catalyst. The designed catalyst was prepared using sol gel-impregnation method. The textural and surface properties of the synthesized catalyst were elucidated using various analytical techniques including EDX, FTIR, XRD, SEM, BET and XPS. The catalyst provided highest biodiesel yield of 95.2 % under the optimized reaction conditions. The successful synthesis of biodiesel was confirmed by GCMS, NMR and FTIR analysis, whereas; the various physiochemical properties were investigated according to the ASTM and EN standards. The designed catalyst showed substantial reproducibility and recyclability up to four times. The mechanism for xK2O/ZrO2-Bi2O3 catalyzed transesterification reaction of WOSO was also proposed. The kinetics studies revealed that the reaction follows pseudo first order and the Ea was calculated to be 32.58 kJ mol−1.

A Novel Mesoporous SBA‐15 Supported Bifunctional Heterogeneous Catalyst for Base‐Free Transfer Hydrogenation Reaction of Ketones

ABSTRACTAmong the problems encountered in the catalytic transfer hydrogenation reactions of ketones, the base sensitivity of ketones and the corrosive effects of the bases used in the reaction have an important place especially in industrial terms. Although there are various approaches to overcome this problem, solutions based on the intrinsic properties of the catalyst used seem more suitable. Within the scope of this study, a novel heterogeneous catalyst was prepared for the transfer hydrogenation reaction of ketones, which can operate in base‐free environment. To prepare the heterogeneous catalyst, 1,2‐diphenylethane‐1,2‐diamine was first tosylated and then the silyl derivative was synthesized and grafted onto mesoporous silica SBA‐15. Characterizations of the obtained heterogeneous catalyst and SBA‐15 were carried out by X‐ray diffractometer (XRD), N2 sorption, thermogravimetric analysis (TGA), scanning electron microscope (SEM), energy dispersive X‐ray analysis, and Fourier transform infrared (FT‐IR) analysis. The results obtained showed that the functionalized 1,2‐diphenylethane‐1,2‐diamine compound was successfully immobilized into the SBA‐15 structure. Determination of the catalytic activity of the heterogeneous catalyst was carried out in transfer hydrogenation reactions of various aromatic ketones. After determining the optimum reaction conditions with acetophenone, a conversion rate of (70%) was observed in the acetophenone to 1‐phenylethanol reaction that took place without a base. Under same conditions a higher conversion rate of (73%) was observed in the 4′‐chloroacetophenone to 1‐(4‐chlorophenyl)ethanol reaction. In the reactions performed to determine recyclability, after a 70% conversion rate, 61% and 65% conversion rates, respectively, were observed in the reaction from acetophenone to 1‐phenylethanol under the same conditions.

Modified Biochar Materials From Eucalyptus globulus Wood as Efficient CO2 Adsorbents and Recyclable Catalysts

AbstractHighly porous carbon materials derived from renewable resources constitute a promising and sustainable strategy regarding the enhancement of CO2 capture technologies. In this work, the valorization of Eucalyptus globulus wood, a forest invasive species present in European forests, is performed through its transformation in biochar. The deposition of nitrogen and different metals (aluminum, copper and chromium) onto biochar is performed, using the magnetron sputtering as a pioneering technique, to produce coated biochar nanoparticles with improved properties. The resultant modified biochar particles maintain a highly porous structure and present a remarkable CO2 adsorption capacity (up to 4.80 mmol g−1 for N@BC), which is attributed to the synergy of their large total surface area (527 m2 g−1) and microporosity (pore diameter = 21 Å), with a high content of nitrogen and oxygen heteroatom moieties (40.4% N, 11.4% O). Their application as heterogeneous bifunctional catalysts in CO2 cycloaddition to epichlorohydrin is performed, in the absence of any solvent or co‐catalyst, under moderate conditions (20 bar CO2, 120 °C), leading to good conversions (up to 58% conversion) and excellent selectivity for cyclic carbonates. Cu‐coated biochar is shown to be more stable than non‐modified material, being recycled and reused along 4 consecutive runs without loss of catalytic activity or selectivity.

A novel Eu8 cluster for efficiently catalyzing CO2 cycloaddition and Knoevenagel condensation

A novel Eu8 cluster, namely, [Eu8(acac)4(HL)4(L)2(μ3O)4 (C2H5O)4]·2C2H5OH·2CH2Cl2 (H2L = 2‑hydroxy-benzoic acid (5-hydroxymethyl-furan-2-ylmethylene)-hydrazide, Hacac = acetylacetone) (1) was assembled using a multidentate ligand H2L. X-ray diffraction analyses reveal that cluster 1 includes eight Eu(III) ions, four HL− ligands, two L2− ligands, four acac−, four μ3O and four coordinated C2H5O−. The Eu8 cluster 1 displays well thermostability. Of particular significance, cluster 1 demonstrated high efficacy in catalyzing the cycloaddition reactions between CO2 and epoxides, as well as Knoevenagel condensation reactions involving aldehydes and malononitrile. This study presents the novel finding that the Eu8 cluster, acting as a remarkable heterogeneous bifunctional catalyst, can effectively facilitate the simultaneous reactions of epoxides with CO2 and Knoevenagel condensation reactions.

Synthesis and characterization of bentonite-based NiO nanoparticles as bi-functional heterogeneous catalyst for efficient synthesis of 1,8-dioxo-decahydroacridines

A straightforward, expeditious, robust, and efficient synthesis of NiO@Bentonite nanocatalyst was done using a simple microwave method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), Brunauer–Emmett–Teller (BET), thermal behavior analysis, and vibrating sample magnetometer (VSM) techniques were used to characterize the physicochemical properties of the NiO@Bentonite nanocomposites. The outcomes demonstrated that the NiO nanoparticles are evenly distributed throughout the Bentonite surface and that the NiO@Bentonite nanocomposites have a high specific surface area and rich pore structure. The following report details the investigation of this catalyst for the preparation of 1, 8-dioxodecahydroacridine heterocycles in a one-pot, three-component reaction of aromatic aldehydes, dimedone, and aniline. After the conditions were optimized, the results demonstrated that this reaction could be carried out in an aqueous medium with a good yield.

Efficacy of tethered Pyridinium-Based ionic liquid immobilized on Zn-MOF-NH2 for effectively converting CO2 into cyclic carbonates under Co-Catalyst-free and solvent-free conditions

A new bifunctional heterogeneous catalyst system was developed by immobilization of pyridinium-based ionic liquid on Zn-MOF-NH2 to produce an IL-supported Zn-MOF-NH2 catalyst. The dual-functional one-component system, including both Lewis acid sites and IL functional sites, showed high catalytic activity for the CO2-epoxide cycloaddition reactions under mild solvent-free conditions. Different techniques such as FE-SEM, EDX, FT-IR, XRD, and BET were applied to characterize of the as-prepared catalyst. This efficient low-leaching catalyst system is separated by centrifugation and can be reused successfully for four successive cycles without altering the catalytic activity in CO2 epoxidation to cyclic carbonates. Due to the wide variety seen in both metal–organic frameworks (MOFs) and ionic liquids (ILs), we believe that this research represents a significant step forward in the potential applications of synthetic modification methods within MOFs.

One-pot catalytic conversion of sugars to methyl lactate over acid-base bifunctional Sn/MgO catalysts

Alkyl lactates represent such green added-value chemicals that commonly used as biodegradable green solvents, detergents, pharmaceutical intermediates et al. Catalytic conversion of carbohydrates to methyl lactate (MLA) is a representative way for high-value utilization of biomass and the key lies in the development of highly efficient catalysts. In methanol, strong acid or alkaline catalysts are usually used under high temperature and high pressure, suffering from problems such as low selectivity, high cost or contamination of environment. This study aims to develop an acid-base bifunctional heterogeneous catalyst for the one-pot conversion of sugars to MLA under mild conditions. Sn/Mg composite oxides was synthesized by a coprecipitation method and further modified by poly (vinyl imidazole) ([PVIM]) to tune the hydrophilicity. Effect of polymer and Sn amount, calcination temperature, reaction temperature, catalyst dosage, and substrate concentration were investigated. The acid-base properties were characterized by NH3-TPD, pyridine-FTIR and CO2-TPD analysis. It was found that the presence of medium acid sites and medium base sites played an important role to the cascade reactions of carbohydrates to MLA. An optimum MLA yield of 55.4% was achieved over 10[PVIM]-5Sn/MgO (0.05 g) with complete conversion of glucose (28 mM) at 140 ℃, 2 MPa N2 for 10 h. The reaction conditions are mild and no strong acid or strong base catalyst is required. Furthermore, a possible reaction mechanism was proposed that the introduction of [PVIM] effectively regulated the local microenvironment of active sites and the acid base synergism greatly promoted the retro-aldol condensation, dehydration and hydrogen transfer reactions during the conversion of glucose to MLA.

Bifunctional heterogeneous catalyst: A sustainable route for cyclic acetals synthesis through tandem hydroformylation-acetalization reaction

A novel sustainable approach for the synthesis of 2-ethyl 1,3 dioxolane and various short to long-chain or aromatic cyclic acetals through a tandem hydroformylation-acetalization reaction using Rh oxide nanoparticle supported on zirconium phosphate has been established. The Rh oxide nanoparticle supported on zirconium phosphate was synthesized and characterized by various physicochemical methods. The SEM and TEM analysis revealed the average particle size of rhodium oxide was found to be ∼7.56 nm in 2%Rh@ZrP catalyst. Furthermore, the synthesized catalyst was employed to carry out a tandem hydroformylation reaction in a green solvent (ethylene glycol). Experimental results demonstrated that 2 wt.% of Rhodium on zirconium phosphate efficiently activated olefins, leading to the selective formation of cyclic acetals (60–99%) at 80°C for 6 h. In this cascade reaction, significant selectivity towards the desired product, linear cyclic acetals was observed for styrenes. This can be attributed to highly dispersed Rh oxide nanoparticles and plentiful acidic sites on the zirconium phosphate supports, which played a crucial role in tandem hydroformylation and acetalization reactions. The catalyst exhibited the ability to be reused three times without losing significant catalytic activity or selectivity. This is the first report on the synthesis of a fuel additive and other cyclic acetals via a tandem hydroformylation-acetalization reaction using heterogeneous catalysts.

Porous carbonaceous materials simultaneously dispersing N, Fe and Co as bifunctional catalysts for the ORR and OER: electrochemical performance in a prototype of a Zn-air battery.

Infiltration of the mesoporous structure of SBA-15 silica as a hard template with phenanthroline complexes of Fe3+ and Co2+ allowed the simultaneous dispersion of nitrogen, iron and cobalt species on the surface of the obtained carbonaceous CMK-3 silica replica, with potential as bifunctional heterogeneous catalysts for the cathodic oxygen reduction and evolution reactions (ORR and OER). The textural properties and mesopore structure depended on the composition of the material. The carbonaceous FeCoNCMK-3 (1/1), obtained with an Fe/Co molar ratio of 1/1, exhibited an ordered cylindrical mesoporous structure with a high mesopore volume, a rather homogeneous composition in terms of total and surface concentrations of iron and cobalt, and a balanced presence of pyridinic-, pyrrolic- and graphitic-N species. FeCoNCMK-3 (1/1) could improve the ORR kinetics by adsorption and reduction of O2 through the 4-electron mechanism with a current density of -17.37 mA cm-2, Eonset of 1.13 V vs. RHE and E1/2 of 0.75 V when compared to metal-free, monometallic or bimetallic electrocatalysts with a higher amount of cobalt than that of iron. In addition, FeCoNCMK-3 (1/1) exhibited activity for the OER, presenting lower values of Eonset (1.52 V), Ej10 (1.78 V) and the Tafel slope (76.3 mV dec-1) with respect to other catalysts. When evaluated as a cathode in a prototype of a Zn-air battery, FeCoNCMK-3 (1/1) exhibited a high open circuit voltage of 1.41 V, a peak power density of 66.84 mW cm-2, a large specific capacity of 818.88 mA h gZn-1, and cycling for 20 h but with deactivation upon cycling.

Fabrication of MoS2/rGO hybrids as electrocatalyst for water splitting applications.

Environmental degradation and energy constraint are important risks to long-term sustainability in the modern world. Water splitting is a vital approach for environmentally friendly and sustainable energy storage, providing a clean way to produce hydrogen without pollutants. Preparing a catalyst that is active, bifunctional, and durable for water splitting is a difficult task. We addressed the difficulty by creating a bifunctional heterogeneous catalyst, MoS2/rGO, with an ideal weight percentage of 5 wt% by a hydrothermal process. The optimized sample showed exceptional electrocatalytic activity, requiring an overpotential of 242 mV and 120 mV to achieve a current density of 10 mA cm-2 in the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER). Furthermore, our synthesized catalyst was validated for its exceptional water-splitting capacity, with the optimized sample showing low Tafel slope values of 59 mV dec-1 for HER and 171 mV dec-1 for OER. The significant OER and HER activity seen in the 5 wt% MoS2/rGO hybrid, compared to other hybrids, is due to the many catalytic active sites that aid in charge and electron transport, as well as the synergistic interaction between MoS2 and rGO.

Sulfonic acid-modified MOFs as heterogeneous bifunctional catalysts for ethylene oligomerization at room temperature without cocatalysts

Ethylene oligomerization plays an important role in industrial production.

Designed synergetic bifunctional catalyst based on diverse nucleophilic-functionalized sites for high-efficient CO2 cycloaddition under co-catalyst and solvent-free conditions

Nucleophilic substitutes provide a new platform to design and synthesize novel bifunctional heterogeneous catalysts for carbon dioxide cycloaddition reaction with epoxides. Herein, in this work, UMCM-15 was fabricated and modified with various nucleophilic ligands containing bromine, amine and hydroxyl functional groups. The resultant prepared compounds were utilized as bifunctional synergetic catalysts for the chemical fixation of carbon dioxide. The catalysts can efficiently catalyze epoxides and carbon dioxide under relatively mild conditions in the absence of co-catalyst and solvent. The contemporaneous presence of Lewis acid and basic centers in the framework resulted in high catalytic activity and turnover number (TON) value for the production of cyclic carbonates compared to other reported compounds indicating superiority of the synthesized catalysts. Among diverse applied bifunctional catalysts, bromine-functionalized frameworks exhibited the highest catalytic performance owing to the presence of multiple electron pairs and the great tendency to donate electron pairs.

Phosphonium Salt/Al‐Porphyrin Copolymer as Bifunctional Heterogeneous Catalyst for CO2 Conversion to Cyclic Carbonates

AbstractThe effective chemical valorization of CO2 by means of its conversion into valuable products is now more than ever a topic of considerable interest. It is on that basis that herein we have chosen the conversion of CO2 and epoxides to cyclic carbonates as a convenient route to achieve this goal. A new bifunctional (Lewis acid/nucleophile) heterogeneous material, TSP‐AlCl‐PhospBr, was designed in order to guarantee a close proximity between the two active sites that can cooperate to the activation and opening of the epoxide ring. The prepared copolymer has been extensively characterized using various spectroscopic and analytical techniques. As a heterogeneous catalyst, it enables efficient chemical conversion of CO2 and epoxides, even at low temperatures, down to 30 °C, without the use of solvents. In particular, the catalyst demonstrates high turnover numbers (TON) and frequency values (TOF). Recyclability studies on TSP‐AlCl‐PhospBr have shown its stability and reusability for consecutive cycles without the need of reactivation procedures.

Boron Bifunctional Catalysts for Rapid Degradation of Persistent Organic Pollutants in a Metal-Free Electro-Fenton Process: O2 and H2O2 Activation Process.

Metals usually served as the active sites of the heterogeneous bifunctional electro-Fenton reaction, which faced the challenge of poor stability under acidic or even neutral conditions. Exploring a metal-free heterogeneous bifunctional electro-Fenton catalyst can effectively solve the above problems. In this work, a stable metal-free heterogeneous bifunctional boron-modified porous carbon catalyst (BTA-1000) was synthesized. For the BTA-1000 catalyst, the yield of H2O2 (294 mg/L) significantly increased. The degradation rate of phenol by BTA-1000 (0.242 min-1) increased by an order of magnitude, compared with the porous carbon catalyst (0.0105 min-1). The BTA catalyst could rapidly degrade industrial dye wastewater, and its specific energy consumption was 5.52 kW h kg-1 COD-1, lower than that in previous reports (6.38-7.4 kW h kg-1 COD-1). DFT and XPS revealed that C═O and -BC2O groups jointly promoted the generation of H2O2, and the -BCO2 group played dominant roles in the generation of •OH because the oxygen atom near the electron-giving groups (-BCO2 group) facilitated the formation of hydrogen bond and H2O2 adsorption. This work gained deep insights into the reaction mechanism of the boron-modified porous carbon catalyst, which helped to guide the development of metal-free heterogeneous bifunctional electro-Fenton catalysts.

Highly cross-linked bifunctional magnesium porphyrin-imidazolium bromide polymer: Unveiling the key role of co-catalysts proximity for CO2 conversion into cyclic carbonates

Highly cross-linked materials containing an imidazolium salt and magnesium porphyrin, either in the absence (TSP-Mg-imi) or in the presence (7a and 7b) of multi-walled carbon nanotubes (MWCNTs), were synthesized and used as heterogeneous bifunctional catalysts for the conversion of CO2 into cyclic carbonates. The metalloporphyrin moiety acts both as a “covalent swelling agent”, generating hybrids with high surface area, and as a Lewis acid co-catalytic species. TSP-Mg-imi produced excellent conversion and TONMg values, under solvent-free conditions, even at room temperature and with low catalytic loading (0.003 mol%). In terms of conversion and TONMg, TSP-Mg-imi exhibited better catalytic performance compared to a reference homogeneous system, demonstrating that the proximity between the metal centers and the nucleophilic site results in a synergistic effect during the catalytic cycle. The results of the computational study confirmed both the cooperative function and the significance of incorporating a co-catalytic species into the system.

Process optimization for blended waste frying oil in biodiesel production using CaO derived from African periwinkle shell catalyst through response surface methodology

Biodiesel is one of the renewable energy alternatives for fossil fuel because of its biodegradability, no toxicity, and environmentally friendly nature. Investigations have been made on transesterifying blended waste frying oil (BWFO) into biodiesel using African periwinkle shells (APS) heterogeneous catalyst. The BWFO, a mixture of 60:40 groundnut oil and waste palm oil, usually causes serious environmental problems when indiscriminately disposed. After being calcined, the non-activated APS (RAPS) was further sulphonated to create an acid-activated APS (AAPSA) catalyst. Scanning electron microscopy (SEM), X-ray fluorescence (XRF), the Brunauer-Emmett-Teller method (BET), and other techniques were used to characterize the produced RAPS and AAPSA. Gas chromatography-mass spectrometry (GC-MS) and Fourier-Transform Infrared Spectroscopy (FTIR) were used to evaluate the produced biodiesel. Besides, a series of physiochemical properties including acid value, density, kinetic viscosity, flash point, cloud point, pour point, and other fuel properties of produced BWFO, were evaluated using ASTM standard methods. The central composite design (CCD) of the response surface methodology (RSM) was utilized for modeling and process optimization of biodiesel production from BWFO.The characterization results revealed that CaO (62.07 %) is the main constituent of AAPSA. The RPSA's pore volume and BET surface area were 0.34 cm3/g and 68.93 m2/g, respectively. BET surface area (30.9%) and pore volume (48.2 %) increased for the AAPSA. The significant increase in surface area and pore volume of AAPSA indicates an enhanced number of acid sites and catalytic activity of the acid-modified catalyst towards higher produced biodiesel yield. The optimal conditions for the reaction temperature, reaction time, catalyst loading, and methanol to oil ratio (mtOH/oil) were 55 °C, 142.5 min, 2.5 wt%, and 14.25:1. This resulted in the maximum yield of biodiesel, which was 91.5 %. Moreover, the AAPSA catalyst performed excellently, and the resulting biodiesel fuel's properties are comparable with those of ASTM D6751 and EN 14214 standards. Hence, AAPSA is a potential solid acid bifunctional heterogeneous catalyst to produce biodiesel from BWFO. Therefore, this study's novelty comprises the synthesis of solid acid bifunctional heterogeneous catalyst from giant African land snail shells and the optimization of the process variables involved in the production of biodiesel from BWFO.

A new 2D coordination polymer as bifunctional heterogeneous catalyst for tandem deacetalization‐Knoevenagel reaction

Designing multifunctional catalysts for one‐pot organic transformations is highly important due to economic and environmental point of views. Synthesis of bifunctional acid–base tandem catalysts has drawn attention owing to the incorporation of antagonistic active sites in a single catalyst. In the current work, a novel coordination polymer, [NaZn(btc)(H2O)3].1.5H2O (1) (1,3,5‐benzenetricarboxylic acid [H3btc]), was prepared by solvothermal method. Single crystal analysis of 1 revealed that the structure is two dimensional and contains the coexisted Lewis acid–base sites. The material was further characterized by powder X‐ray diffraction, FT‐IR, thermogravimetric analysis, and temperature programed desorption of NH3 (NH3‐TPD) and CO2 (CO2‐TPD). Compound 1 was utilized as a heterogeneous catalyst for tandem deacetalization‐Knoevenagel reaction of benzaldehyde dimethyl acetal and malononitrile. It exhibited good activity and structural stability during the reaction.

A rapid synthesis of quinoxalines by using Al2O3–ZrO2 as heterogeneous catalyst

In this study, we present a highly efficient and environmentally benign protocol for synthesizing biologically important quinoxaline derivatives. The synthesis involves the reaction of 1,2-diamines with substituted phenacyl bromides or benzil, taking place at room temperature in N,N-dimethylformamide (DMF) solvent. The reaction is facilitated by a bifunctional heterogeneous catalyst composed of Al2O3–ZrO2 binary metal oxide. Our method offers numerous advantages, including excellent product yield, renewable catalytic conditions, minimal catalyst usage, safer chemistry, short reaction time, and a simple work-up procedure. To determine the chemical structure of the synthesized derivatives, we employed characterization techniques such as nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). Additionally, the Al2O3–ZrO2 catalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDAX), and thermogravimetric analysis (TGA).

Ligand-Field Directed Electronic Effects in Heterogenized Bifunctional Co(II) Molecular Clusters Accomplish Efficient Overall Water Splitting

We demonstrate a hitherto unknown approach of employing cobalt organophosphate D4R cage-clusters, [(RO) PO3Co(L)]4 (1–4) and [nBu4N][F@{(RO)PO3Co(L)}4], (1F–4F), where L = DMSO (1 or 1F), pyridine (2 or 2F), 4-formylpyridine (3 or 3F), and 4-cyanopyridine (4 or 4F), as bifunctional heterogeneous catalysts for electrochemical water splitting in near-neutral conditions. Electronic and steric modifications on the clusters are achieved through a synergistic combination of endohedral trapping of fluoride ion and exohedral functionalization of pyridines. This two-pronged approach significantly reduces the charge density at the metal leading to energetically favorable water coordination with a perceptible enhancement in the kinetics of overall water splitting, with 4F exhibiting the lowest cell overpotential of 0.949 V (overall cell potential 2.179 V), observed among molecular catalysts. Density functional calculations highlight the importance of cooperativity between the cobalt centers. The unique D4R geometry stabilizes the high-valent metal-oxo/hydroperoxo species, emphasizing the need for polynuclear clusters to catalyze such challenging reactions, as has been well-established in the evolutionary PS-II.