Turnover Frequency Research Articles

Vertically Expanded Covalent Organic Frameworks for Photocatalytic Water Oxidation into Oxygen

Covalent organic frameworks with unique π architectures and pores could be developed as photocatalysts for transformations. However, they usually form π‐stacking layers, so that only surface layers function in photocatalysis. Here we report a strategy for developing vertically expanded frameworks to expose originally inaccessible active sites hidden in layers to catalysis. We designed covalently linked two‐dimensional cobalt(II) porphyrin layers and explored coordination bonds to connect the cobalt(II) porphyrin layers with bidentate ligands via a three‐component one‐pot polymerization. The frameworks expand the interlayer space greatly, where both the up and down faces of each cobalt(II) porphyrin layer are exposed to reactants. Unexpectedly, the vertically expanded frameworks increase skeleton oxidation potentials, decrease exciton dissociation energy, improve pore hydrophilicity and affinity to water, and facilitate water delivery. Remarkably, these positive effects work collectively in the photocatalysis of water oxidation into oxygen, with an oxygen production rate of 1155 µmol g−1 h−1, a quantum efficiency of 1.24% at 450 nm, and a turnover frequency of 1.39 h−1, which is even 5.1‐fold as high as that of the π‐stacked frameworks and ranks them the most effective photocatalysts. This strategy offers a new platform for designing layer frameworks to build various catalytic systems for chemical transformations.

Vertically Expanded Covalent Organic Frameworks for Photocatalytic Water Oxidation into Oxygen.

Covalent organic frameworks with unique π architectures and pores could be developed as photocatalysts for transformations. However, they usually form π-stacking layers, so that only surface layers function in photocatalysis. Here we report a strategy for developing vertically expanded frameworks to expose originally inaccessible active sites hidden in layers to catalysis. We designed covalently linked two-dimensional cobalt(II) porphyrin layers and explored coordination bonds to connect the cobalt(II) porphyrin layers with bidentate ligands via a three-component one-pot polymerization. The frameworks expand the interlayer space greatly, where both the up and down faces of each cobalt(II) porphyrin layer are exposed to reactants. Unexpectedly, the vertically expanded frameworks increase skeleton oxidation potentials, decrease exciton dissociation energy, improve pore hydrophilicity and affinity to water, and facilitate water delivery. Remarkably, these positive effects work collectively in the photocatalysis of water oxidation into oxygen, with an oxygen production rate of 1155 µmol g-1 h-1, a quantum efficiency of 1.24% at 450 nm, and a turnover frequency of 1.39 h-1, which is even 5.1-fold as high as that of the π-stacked frameworks and ranks them the most effective photocatalysts. This strategy offers a new platform for designing layer frameworks to build various catalytic systems for chemical transformations.

A facile and green procedure in preparing dibenzo-chromeno-phenazine-diones using an effectual and recyclable Brønsted acidic ionic liquid

First, a Brønsted acid ionic liquid (BAIL) in the role of a double acid-base called 1,3-n-propyl-bipyridinium bisulfonic acid-ditrifluoroacetate (PBPBSDT) was produced, and its skeleton was determined via TGA, mass, 13C NMR, 19F NMR, 1H NMR and FT-IR data. Further, it was successfully applied in the preparation of dibenzo-chromeno-phenazine-dione derivatives (1a-12a, 9–15 min, 90–98%) via one-pot multicomponent domino reaction among 2 mmol 2-hydroxynaphthalene-1,4-dione, 1 mmol benzene-1,2-diamine, and 1 mmol aldehydes under optimal conditions (5 mol% of PBPBSDT, solvent-free, 60 °C). The proper reproducibility of the PBPBSDT homogeneous catalyst (5 times), solvent-free medium, reasonable TON (Turnover Number) and TOF (Turnover Frequency) numbers, the non-metallic framework of the catalyst, and the formation of C-N, C = N, C-C, C = C, C-O bonds in a single operation are the distinct advantages of this protocol.

Atomically precise copper clusters with dual sites for highly chemoselective and efficient hydroboration.

The hydroboration of alkynes into vinylboronate esters is a vital transformation, but achieving high chemoselectivity of targeted functional groups and an appreciable turnover number is a considerable challenge. Herein, we develop two dynamically regulating dual-catalytic-site copper clusters (Cu4NC and Cu8NC) bearing N-heterocyclic thione ligands that endow Cu4NC and Cu8NC catalysts with performance. In particular, the performance of microcrystalline Cu4NC in hydroboration is characterized by a high turnover number (77786), a high chemoselectivity, high recovery and reusability under mild conditions. Mechanistic studies and density functional theory calculations reveal that, compared with the Cu8NC catalyst, the Cu4NC catalyst has a lower activation energy for hydroboration, accounting for its high catalytic activity. This work reveals that precisely constructed cluster catalysts with dual catalytic sites may provide a way to substantially improve catalytic properties by fully leveraging synergistic interactions and dynamic ligand effects, thus promoting the development of cluster catalysts.

Role of Active Centers in Predicting the Catalyst Turnover: A Theoretical Study.

Water oxidation catalysis has garnered significant attention due to its potential for sustainable energy conversion. Among molecular catalysts, [Fe(OTf)2 (Me2Pytacn)] complexes have exhibited notable turning-over rates. Although various [M(OTf)2 (Me2Pytacn)] complexes (M = Mn, Co, Ni) have been synthesized, however, the role of active centres has not been thoroughly investigated. In this study, we apply our newly developed catalytic models, efficiency conceptualization model (ECM) and the maximum kinetic efficiency MaxKinEff framework to assess the role of the active centres in its catalytic performance. Our computational analysis identifies cobalt-based [Co(OTf)2 (Me2Pytacn)] as a superior alternative for water oxidation reactions. Notably, cobalt catalysts exhibit a longer lifespan (~ 44 days) and higher turnover numbers (TON), with computed values of (ECM) = 3.30 h-1, (ECM) = 3456, (MaxKinEff) = 12.43 h-1, and (MaxKinEff) = 3616. These findings suggest that cobalt could play a pivotal role in improving the efficiency of molecular catalysts for water oxidation.

Phosphonate-Substituted Pyrazinoporphyrin - a General Photocatalyst for Efficient Sulfoxidation.

An exceptional efficiency of pyrazine-annelated porphyrin as a general photocatalyst for the oxidation of organic sulfides is demonstrated. It is shown that phosphonate-substituted pyrazinoporphyrin 2H-1 brings together sufficient photostability and high efficiency in the aerobic photooxidation of a series of various sulfides. The influence of the reaction conditions onto the efficiency of homogeneous sulfide photooxidation in the presence of the photosensitizer (PS) was investigated and strong dependence on the solvent system was observed. The use of methanol is required for the photocatalytic sulfoxidation and the ratio of the alcohol/other solvent can significantly affect the conversion and selectivity of the reaction. The application of the prepared PS in 0.001 mol % loading allowed achieving complete conversion (97-100 %, turnover number up to 1,00,000, turnover frequency up to 6250 h-1) of substrates bearing substituents of different nature, namely aromatic and aliphatic sulfides with donor or acceptor substituents and substituents prone to oxidation, as well as cyclic sulfides. The selectivity of the of the corresponding sulfoxides formation of 96-100 % was revealed. Finally, a gram-scale synthesis of several sulfoxides was successfully performed with the PS under investigation, providing desired products in 66-96 % yield with over 98 % purity.

Harnessing the optimization of enzyme catalytic rates in engineering of metabolic phenotypes.

The increasing availability of enzyme turnover number measurements from experiments and of turnover number predictions from deep learning models prompts the use of these enzyme parameters in precise metabolic engineering. Yet, there is no computational approach that allows the prediction of metabolic engineering strategies that rely on the modification of turnover numbers. It is also unclear if modifications of turnover numbers without alterations in the host's transcriptional regulatory machinery suffice to increase the production of chemicals of interest. Here, we present a constraint-based modeling approach, termed Overcoming Kinetic rate Obstacles (OKO), that uses enzyme-constrained metabolic models to predict in silico strategies to increase the production of a given chemical, while ensuring specified cell growth. We demonstrate that the application of OKO to enzyme-constrained metabolic models of Escherichia coli and Saccharomyces cerevisiae results in strategies that can at least double the production of over 40 compounds with little penalty to growth. Interestingly, we show that the overproduction of compounds of interest does not entail only an increase in the values of turnover numbers. Lastly, we demonstrate that a refinement of OKO, allowing also for manipulation of enzyme abundance, facilitates the usage of the available compendia and deep learning models of turnover numbers in the design of precise metabolic engineering strategies. Our results expand the usage of genome-scale metabolic models toward the identification of targets for protein engineering, allowing their direct usage in the generation of innovative metabolic engineering designs for various biotechnological applications.

Borenium Ion Equivalents Stabilized by BICAAC and Their Implementation as Catalysts in Hydrosilylation of Carbonyls.

Hydride abstraction from the borane adduct, (BICAAC)‧BH3 afforded the hydride bridged dinuclear borenium ion equivalent complexes 1 and 2 that have been characterized by various spectroscopic and spectrometric techniques followed by the assessment of Lewis acidity using the Gutmann-Beckett method. The single crystal X-ray structure of complex 2 revealed the presence of discrete ions in the solid state. The complex (BICAAC)‧BH2(OTf) (3), obtained from the reaction of (BICAAC)‧BH3 with MeOTf, forms the corresponding boronium cations [(BICAAC)‧BH2(L)]+(OTf)- on reaction with Lewis bases (L = pyridine (4) and DMAP (5)). Complexes 1 and 2 demonstrated notable catalytic activity in the hydrosilylation of a diverse array of carbonyls using 1.0 mol% catalyst loading (achieving the highest turnover frequency (TOFmax) of up to 1200 h-1 with benzaldehyde. A broad substrate scope has been presented for aldehydes and ketones decorated with various electron-donating and withdrawing substituents along with this the hydrosilylation of a few para-quinone methides has also been presented.

Satellite Pd Single-Atom Embraced AuPd Alloy Nanoclusters for Enhanced Hydrogen Evolution.

The fabrication of hybrid active sites that synergistically contain nanoclusters and single atoms (SAs) is vital for electrocatalysts to achieve excellent activity and durability. Herein, we develop a ligand-assisted pyrolysis strategy using nanoclusters (Au4Pd2(SC2H4Ph)8) with alloy cores and protected ligands to build AuPd cluster sites embraced by satellite Pd SAs. In the thermal drive control process, different thermodynamic properties of the alloy atoms and the confinement effects of organic ligands allow for the mild spillover of the single-component metal Pd, resulting in the formation of AuPd alloy nanoclusters tightly encompassed by isolated Pd atoms. Experiments and theoretical calculations indicated that the satellite Pd atoms can optimize the electronic structure of the AuPd nanoclusters and Au sites in the alloy to facilitate the adsorption and dissociation of H2O, thus enhancing the hydrogen evolution reaction (HER) activity. The optimal AuPdNCs/PdSAs-600 exhibits outstanding electrocatalytic activity toward HER, with overpotentials of 21 and 38 mV at 10 mA cm-2 in acidic and alkaline media, respectively. Moreover, the mass activity and turnover frequency of AuPdNCs/PdSAs-600 are one order of magnitude higher than those of commercial Pd/C and Pt/C catalysts. This facile strategy for constructing hybrid catalytic centers using ligand-protected nanoclusters provides efficient insights for the further design of nanocluster-based electrocatalysts synergized by SAs.

Organic-Inorganic Hybrid Perovskite for Ferroelectric Catalysis.

Organic-inorganic hybrid perovskite ferroelectric has gained significant attention for its structural flexibility and diversity. They can directly utilize metal nodes and organic groups as active sites in catalysis. Additionally, their ferroelectric polarization occurs around these active sites, significantly enhancing catalytic activity and demonstrating immense potential for applications. However, their catalytic applications remain underexplored. This work marks the first utilization of the molecular perovskite ferroelectric [3,3-difluorocyclobutylammonium]2CuCl4 (Cu-DFCBA) as a catalyst for alkane oxidation. Under ultrasonic stimulation, it achieved a remarkable turnover number as high as 2402. Compared to inorganic ferroelectrics like lithium niobate (LiNbO3), the molecular ferroelectric exhibited a 1200-fold increase in catalytic activity. This highlights Cu-DFCBA's robust ferroelectric properties and underscores the vast potential of molecular ferroelectrics in catalysis, guiding future system designs.

Oxidation of alcohols to carbonyl compounds with H2O2 in water catalyzed by polyoxometalate-based hyper-crosslinked ionic polymer

The oxidation reaction involving hydrogen peroxide (H2O2) in water is of great attraction in fundamental research and industrial application, but there is still a long way to go. Herein, a new hybrid catalyst PW@Py-HIP was successfully synthesized by immobilization of phosphotungstic anions onto/into the pyridinium-based hyper-crosslinked ionic polymer using a post-synthetic strategy. This facile synthetic method afforded heterogeneous catalyst with a large specific surface area of 428.7 m2·g−1 and stable polymeric skeleton. The amphiphilic PW@Py-HIP exhibited remarkable catalytic activity and quantitative selectivity for the oxidation of alcohols into carbonyl compounds with H2O2 in water. The turnover frequency (TOF) and turnover number (TON) values reached 1088.9 h−1 and 4083.3, respectively. Owing to its good heterogeneous nature, PW@Py-HIP can be recycled for six times without significant loss of activity. The developed catalytic system confirmed to be beneficial toward the synthesis of related carbonyl compounds from various alcohols with appreciable conversions.

A novel method for engineering active sites through in-situ and chemical deposition: Robust Ni3S2/MoS2/WS2 heterostructures for efficient water splitting in an alkaline medium

To develop compact and efficient electrolysers, use a bi-functional electrocatalysts capable of performing both the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) at the same temperature, pressure, and pH. To develop ternary transition metal sulphides for OER and HER with superior performance. Herein, reported a sheet-like heterostructures electrode made of was fabricated on nickel foam using a simple hydrothermal method. The surface morphology and electrochemical active sites of the binder-free NMWS(1:1) heterostructures bi-functional catalyst were analysed in a 1.0 M KOH electrolyte medium to attain a lower overpotential for both OER (290 mV @ 10 mA cm−2) and HER (165 mV @ 10 mA cm−2). Electrochemical NMWS (1:1) studies show that the purported efficiencies are due to increased oxygen vacancies, interfacial bonds, and surface sulfur sites in the heterostructures were analysed through XPS, and HR-TEM. Furthermore, a dual-electrode in an electrolyser cell, the proposed heterostructures electrode achieved a current density of 10 mA cm−2 yet retained a remarkably low cell voltage of 1.73 V. The Ni3S2/MoS2/WS2 heterostructures stabilizes, which helps maintain LSV's low current degradation rate (CDR). The efficient water splitting has been calculated using turnover frequency and Tafel plot.

Single nickel atoms anchored on porous N-doped nanocarbon with dual reaction sites for highly-efficient transfer hydrogenation of furfural to furfuryl alcohol

The non-precious metal single-atom catalysts (SACs) supported on carbon materials for the catalytic transfer hydrogenation (CTH) of α,β-unsaturated aldehydes (UAL) still suffer from the problems of harsh reaction conditions and low activity. In this work, nickel SACs anchored on porous N-doped nanocarbon (Ni1/NC900) with dual reaction sites were synthesized using the high internal-phase emulsion (HIPE) template method combined with impregnation. The Ni1/NC900 catalyst exhibited remarkable catalytic activity for the CTH of furfural (FF) to furfuryl alcohol (FFA), achieving >99.0 % conversion and selectivity at 100 °C for 60 min, with a turnover frequency (TOF) of 2908.1 h−1, surpassing other reported nickel-based catalysts by 1–3 orders of magnitude. The excellent catalytic performance of Ni1/NC900 was attributed to the high mass transfer efficiency (HMTE) of the support and the dual reaction sites of Ni–N4 and pyridinic N, where Ni–N4 as Lewis acidic site for adsorption of FF and isopropanol (i-PrOH), while the adjacent pyridinic N as Lewis basic site for the deprotonation of i-PrOH. The isotope labeling experiments revealed that the hydrogenation of FF was accomplished by proton transfer with i-PrOH, in agreement with the intermolecular hydride transfer mechanism. Furthermore, Ni1/NC900 demonstrated excellent stability and well general applicability, demonstrating its potential for industrial applications. This work provides a reference for the application of carbon-based non-precious metal SACs in the CTH reaction of UAL.

Selective Electrochemical CO2 Reduction to Ethylene and Multi-carbon Products on Oxide-derived Porous CuO Micro-cages

The electrochemical reduction of CO2 (CO2RR) presents a dual benefit: it helps mitigate environmental pollution while producing valuable multi-carbon (C2+) chemicals and storing renewable energy in chemical fuels. However, there is an urgent need for efficient electrocatalysts that can selectively increase the production of ethylene and C2+ products for the wide-scale implementation of CO2RR. Herein, we have facilely synthesized porous micro-caged oxide-derived copper oxide (OD-Cu MC) using a one-pot hydrothermal approach followed by air-annealing at 350 °C. The resulting electrocatalyst exhibited excellent performance for ethylene (C2H4) production, achieving a faradaic efficiency (FE) of 44.8 % for C2H4 and cumulative FE of 73.1 % for C2+ products at current density (ID) of 300 mA cm−2. At an ID of 400 mA cm−2, OD-Cu MC demonstrated a turnover frequency (TOF) of 0.012 s−1 for ethylene, which is 7.8 times higher than the TOF observed for commercially available copper oxide (CuO-CM). Moreover, at an ID of 300 mA cm−2, OD-Cu MC achieved a single-pass CO2 conversion (SPCC) of 35.2 % and a half-cell energy efficiency of 15.6 % for C2+ products. The catalyst also showed good stability, maintaining its performance for over 4 h at an ID of 200 mA cm−2. This straightforward synthesis approach opens new avenues for enhancing C2+ product selectivity in CO2RR.

Construction of Co-Ni3B/GDY heterostructured electrocatalyst for boosting oxygen evolution in alkaline media

Water splitting as the clean technology for hydrogen production garnered the widespread attention. The high overpotential required for oxygen evolution reaction (OER) is the central dilemma. Herein, Co-Ni3B/graphdiyne heterostructure on copper foam (Co-Ni3B/GDY/CF) was constructed for boosting alkaline OER. Detailed electrochemical analysis showed that Co-Ni3B/GDY/CF was an exceptional OER electrocatalyst with the low overpotentials of 270 and 335mV at 20 and 100mAcm−2 in 1.0M KOH solution, respectively, as well as high turnover frequency of 0.80s−1 at 400mV. Moreover, its catalytic performance outperformed the benchmarked RuO2/CF when the current density exceeded 200mAcm−2. Importantly, the equipped electrolyser Pt/C/CF||Co-Ni3B/GDY/CF showed low cell voltage (1.53V@10mAcm−2) and long-term durability. These results demonstrated that a synergistic effect at the heterointerface between GDY and Co-Ni3B was achieved, which regulated the electronic configuration, accelerated the charge transfer and increased the active surface areas. Furthermore, the density functional theory calculations revealed that Co-Ni3B/GDY with incomplete charge transfer lowered the energy barrier of the rate-determining step and optimized adsorption/desorption behavior of the intermediates, thereby effectively promoting O2 evolution.

Activity-Based Dicyanoisophorone Derivatives: Fluorogenic Toolbox Enables Direct Visualization and Monitoring of Esterase Activity in Tumor Models.

The visualization and spatiotemporal monitoring of endogenous esterase activity are crucial for clinical diagnostics and treatment of liver diseases. Our research adopts a novel substrate hydrolysis-enzymatic activity (SHEA) approach using dicyanoisophorone-based fluorogenic ester substrates DCIP-R (R = R1-R6) to evaluate esterase preferences on diverse substrate libraries. Esterase-mediated hydrolysis yielded fluorescent DCIP-OH with a nanomolar detection limit in vitro. These probes effectively monitor ester hydrolysis kinetics with a turnover number of 4.73 s-1 and catalytic efficiency (kcat/Km) of 106 M-1 s-1 (DCIP-R1). Comparative studies utilizing two-photon imaging have indicated that substrates containing alkyl groups (DCIP-R1) as recognition elements exhibit enhanced enzymatic cleavage compared to those containing phenyl substitution on alkyl chains (DCIP-R4). Time-dependent variations in endogenous esterase levels were tracked in healthy and liver tumor models, especially in diethylnitrosamine (DEN)-induced tumors and HepG2-transplanted liver tumors. Overall, fluorescence signal quantifications demonstrated the excellent proficiency of DCIP-R1 in detecting esterase activity both in vitro and in vivo, showing promising potential for biomedical applications.

Formic acid dehydrogenation using Ruthenium-POP pincer complexes in ionic liquids

Formic acid is one of the most promising candidates for the long-term storage of hydrogen in liquid form. Herein, we present a new collection of ruthenium pincer complexes of the general formula [RuHCl(POP)(PPh3)] using commercially available or easy-to-synthesize tridentate xantphos-type POP pincer ligands. We applied these complexes in the dehydrogenation of formic acid to CO2 and H2 using the ionic liquid BMIM OAc (1-butyl-3-methylimidazolium acetate) as solvent under mild, reflux-free conditions. The best performing catalyst with respect to maximum turnover frequency, the literature-known complex [RuHCl(xantphos)(PPh3)] Ru-1, produced a maximum turnover frequency of 4525 h−1 with 74% conversion after 10 min at 90 °C and complete conversion (> 98%) occurring within 3 h. On the other hand, the best overall performing catalyst, the novel complex [RuHCl(iPr-dbfphos)(PPh3)] Ru-2, facilitated full conversion within 1 h leading to an overall turnover frequency of 1009 h−1. Moreover, catalytic activity was observed at temperatures as low as 60 °C. Only CO2 and H2 are observed in the gas phase, with no CO detected. High-resolution mass spectrometry suggests the presence of N-heterocyclic carbene complexes in the reaction mixture.

Binary Iron-Manganese Cocatalyst for Simultaneous Activation of C-C and C-O Bonds to Maximally Utilize Lignin for Syngas Generation over InGaN.

Solar-powered lignin reforming offers a carbon-neutral route for syngas production. This study explores a dual non-precious iron-manganese cocatalyst to simultaneously activate both C-C and C-O bonds for maximizing the utilization of various substituents of native lignin to yield syngas. By assembling with InGaN nanowires on a Si wafer, the as-designed dual FeMn cocatalyst affords a measurable syngas evolution rate of 42.4 mol·gcat-1·h-1 from native lignin in distilled water with a high selectivity of 93% and tunable H2/CO ratios under concentrated light, leading to a considerable light-to-fuel efficiency of 11.8%. The high FeMn atom efficiency arising from the 1-dimensional nanostructure of InGaN enables the achievement of a high turnover frequency (TOF) of 220896 mol syngas per mol FeMn per hour. By correlating explorationexperiments,the critical role of the dual FeMn cocatalyst in the evolving mechanism of lignin and water toward syngas is disclosed at the atomic level. It is discovered that the synergetic iron-manganese cocatalyst supported by InGaN nanowires enables simultaneous activation of C-C and C-O bonds with comparable minimized dissociation energies.This work demonstrates a new and earth-abundant bifunctional cocatalyst for utilizing various substituents of lignin to produce syngas powered by sunlight beyond fossil fuels.

Binary Iron‐Manganese Cocatalyst for Simultaneous Activation of C‐C and C‐O Bonds to Maximally Utilize Lignin for Syngas Generation over InGaN

Solar‐powered lignin reforming offers a carbon‐neutral route for syngas production. This study explores a dual non‐precious iron‐manganese cocatalyst to simultaneously activate both C‐C and C‐O bonds for maximizing the utilization of various substituents of native lignin to yield syngas. By assembling with InGaN nanowires on a Si wafer, the as‐designed dual FeMn cocatalyst affords a measurable syngas evolution rate of 42.4 mol·gcat‐1·h‐1 from native lignin in distilled water with a high selectivity of 93% and tunable H2/CO ratios under concentrated light, leading to a considerable light‐to‐fuel efficiency of 11.8%. The high FeMn atom efficiency arising from the 1‐dimensional nanostructure of InGaN enables the achievement of a high turnover frequency (TOF) of 220896 mol syngas per mol FeMn per hour. By correlating exploration experiments, the critical role of the dual FeMn cocatalyst in the evolving mechanism of lignin and water toward syngas is disclosed at the atomic level. It is discovered that the synergetic iron‐manganese cocatalyst supported by InGaN nanowires enables simultaneous activation of C‐C and C‐O bonds with comparable minimized dissociation energies. This work demonstrates a new and earth‐abundant bifunctional cocatalyst for utilizing various substituents of lignin to produce syngas powered by sunlight beyond fossil fuels.

Propane Dehydrogenation on PtxZny Active Sites in Silicalite‐1

AbstractThe improvement of Pt‐based catalysts for propane dehydrogenation (PDH) has progressed by recent investigations that have identified Zn as a promising promoter for Pt subnanometer catalysts. It is desirable to gain insights into the structure, stability, and activity of such active sites and the factors that influence them, such as Zn : Pt ratio, Pt coordination and nuclearity. Here, we employ density functional theory and microkinetic simulations to investigate the stability of PtxZny (x=1–3, y=0–3) active sites grafted on silanols of Silicalite‐1 and the PDH activity of Pt. We find that the coordination of a Pt atom to a nest of grafted Zn(II) atoms increases the stability of the Pt1Zny sites, whose activity is similar for y=0–2 and drops dramatically for y>2. We further demonstrate, via linear scaling relations and microkinetic simulations, that the turnover frequency obeys a volcano law as a function of propylene binding strength. The Pt2Zn1 and Pt3Zn1 sites are stable and exhibit activity similar to Pt1Zn2, but only Pt1Zn2 manifests reaction kinetics consistent with experimental data, strongly suggesting the active site composition in the synthesized catalyst samples. The methodology presented here suggests a general strategy for deducing active site information such as composition through simple kinetic experiments.