Design Of Catalysts Research Articles

Facile boosting catalytic thermal decomposition of ammonium perchlorate from 3D porous nano Co3O4@ZnO composites

The design of efficient catalysts for the pyrolysis of ammonium perchlorate (AP) is important for the performance of composite solid propellants. Co3O4@ZnO heterojunction composites were fabricated by hydrothermal and calcination treatments and used to promote the thermal decomposition of AP. The influences of the Co/Zn molar ratio on the catalytic performance and the content of decomposition products of AP were investigated by various techniques such as TEM, XPS, BET, EIS, and TG-IR. The results revealed that the Co/Zn = 3 sample exhibited excellent performance with the high-temperature decomposition (HTD) temperature of AP reduced from 410°C to 295 °C and the apparent activation energy decreased to 98.7 kJ/mol in the case of 2 wt% addition, attributed to the construction of a heterojunction with abundant active sites enhancing the charge transfer capability between the Co3O4 and ZnO. The decomposition pathway of AP is influenced by the catalyst components, and the Co/Zn = 3 nanostructures demonstrated outstanding catalytic performance by accelerating the decomposition of HClO4 and the conversion of NH3, and promoting the production of N2O, NO, and NO2. This work provides a feasible strategy for the development of Co3O4@ZnO catalysts with excellent catalytic activity towards AP.

Enhancement of peroxymonosulfate activation through regulating electronic structure of cobalt phthalocyanine by g-C3N4 for rhodamine B degradation

The catalytic performance of cobalt-based catalysts in Fenton-like reactions is significantly influenced by the electron density of Co centers. However, precise control of the electronic structure to enhance the degradation activity remains a challenge. This paper demonstrates a method to enhance the catalytic activity of cobalt phthalocyanine (CoPc) by modulating its electronic structure via integrating with graphitic carbon nitride (g-C3N4). The electron redistribution between g-C3N4 and CoPc was observed, resulting in electron-rich Co centers. Consequently, the CoPc/g-C3N4 composites exhibit significantly enhanced peroxymonosulfate (PMS) activation capability compared to CoPc and their physical mixtures. The improved catalytic performance is due to the electron-rich Co centers, better dispersion of CoPc, and enhanced hydrophilicity. This study proposes a novel strategy for the design of efficient PMS activation catalysts.

Controlled formation of CoOOH/Co(III)-MOF active phase for boosting electrocatalytic alkaline water oxidation

Surface reconstituted metal-organic frameworks (MOFs) offer appealing properties for electrocatalysis due to their unique structural and compositional advantages. In this work, a controlled potential-induced reconstruction of a two-dimensional cobalt metal-organic framework for boosting oxygen evolution reaction in alkaline media is reported. The current MOF is shown to undergo a partial structural transformation that generates a heterogeneous system, where the original MOF coexists with an oxyhydroxide phase. In fact, the potential-induced stabilization of Co(III) metal centers in the MOF is crucial for delaying its full degradation in alkaline media. This partial retention of the Co(III)MOF phase in the so-derived heterogeneous catalyst has been demonstrated to be decisive for boosting the alkaline electrocatalytic oxygen evolution reaction (OER), displaying superior OER activity in terms of both thermodynamic and kinetic merits compared to the benchmark IrO2 and RuO2 electrocatalysts and the prototypical cobalt (oxy)hydroxides, with a Tafel slope of 52 mV dec−1 and a turnover frequency (TOF) of 6.8 s−1 at 450 mV. Remarkably, the generated final product is stable, exhibiting high robustness and long durability for long-term OER electrolysis. This work provides new insight into the impact of the reconstruction of a MOF for alkaline OER under typical electrochemical conditions, which ultimately benefits the rational design of MOF-based catalysts with high electrocatalytic activity for oxidation reactions.

Cu nanoparticles immobilized in mesopores generated in zeolite for high-performing CO2 hydrogenation to methanol

Copper nanoparticles (Cu NPs) are commonly used as catalyst active components in CO2 hydrogenation reactions. However, they often lose their catalytic activity due to sintering in most reaction environments. This study explores a solution for Cu-supported catalysts used for methanol production from CO2 hydrogenation by fixing Cu NPs in the mesopores generated in zeolite. Mesopores were generated in NaY zeolite by partially dealuminating its framework. High-resolution (scanning) transmission electron microscopy (HR(S)TEM) and CO adsorption measurements confirm that the synthesized mesoporous zeolite-supported Cu NPs are highly dispersed and fixed within the mesopores. In comparison with conventional microporous zeolite-supported Cu NPs (2 wt%), Cu NPs (2 wt%, average size of 2.2 nm) in mesoporous zeolite increased methanol production from ∼26 mmolgCu−1h−1 to approximately 56 mmolgCu−1h−1 at 250 °C. By further modifying the mesoporous zeolite with Zr (2 wt%), Cu NPs increased in size, and the methanol production rate increased approximately 2.2 folds to 125 mmolgCu−1h−1 under similar conditions due to zeolite electronic modification and the newly formed Zr-zeolite/Cu interface. However, the addition of Zr significantly increased the Cu NP size and moved part of them out of the mesopores, lowering their stability. In situ DRIFTS experiments reveal CO2 hydrogenation proceeds through the formate route via a direct formation of dominantly carbonate (*CO3), which hydrogenates to formate (*HCOO) and traces of methoxy (*H3CO), and subsequently methanol (CH3OH). This study reports the design of active and stable catalysts for CO2 hydrogenation to methanol by engineering Cu NPs in zeolite pores.

Regulating the N-functional hydrogen bond donors over magnetic nanoparticles supported imidazole tribromide zinc ionic liquid for CO2 cycloaddition

The design of catalysts for the mile production of cyclic carbonates by CO2 cycloaddition is of value. Magnetic polymer nanoparticles-supported imidazole tribromide zinc ionic liquid catalysts, incorporating N-functional hydrogen bond donors (HBD), was successfully accomplished. The correlation between the N-functional HBD and catalytic activity was thoroughly investigated through experimental studies and DFT calculations. The catalyst featuring a secondary amine group (NHM) demonstrated remarkable catalytic performance in CO2 cycloaddition reactions. Under optimized conditions, including 0.12 mol% catalyst dose, 100 °C, and nPO:nCO2 = 1:1.2 for 3 h, a complete conversion was achieved. The exceptional performance of the catalyst was attributed to the multicenter synergistic effect, arising from the appropriate electronegativity, minimal spatial site resistance, a balanced distance between the NHM and imidazolium ion, and the presence of multiple active centers (NHM, Zn2+, and Br−). The integration of a magnetic component enabled swift separation and exceptional recovery stability over 8 consecutive cycles.

Selective hydrogenolysis of furfuryl alcohol to 1,2-pentanediol over CuMg supported on mesoporous silica: Effect of pore size and shape

Utilizing urea homogeneous precipitation method, Cu and Mg species were successfully supported on SBA-15, KIT-6, and MCM-41 respectively for furfuryl alcohol (FFA) hydrogenolysis to 1,2-pentanediol (1,2-PeD). The catalytic results showed that the yield of 1,2-PeD followed the order of CuMg/SBA-15 > CuMg/KIT-6 > CuMg/MCM-41, especially the maximum of 50.0 % over CuMg/SBA-15 surpassing that of most copper-based catalysts reported. It is found that FFA conversion dramatically increases with the raising of Cu dispersion, attributing to the high exposure of active sites. Meanwhile, the selectivity of 1,2-PeD is strongly depended on the Cu0/Cu+ ratio of catalyst and CuMg/SBA-15 with the highest value of 57.6 % is derived from the largest Cu0/Cu+ ratio. In a word, CuMg/SBA-15 shows the excellent activity along with stability owing to the synergy between large Cu0/Cu+ ratio and good Cu dispersion, providing by two-dimensional hexagonal straight channel arrangement with generous pore diameter. Innovatively, it is put forward that dual adsorption sites of both MgO and Cu species in the CuMg/SBA-15 catalyst promote the FFA ring-opening to yield 1,2-PeD based on the comparison of Cu dispersion, metal-support (M−S) interaction and the adsorption capacity for furan rings with Cu/SBA-15. This study provides a novel approach for catalyst design for this reaction, focusing on optimizing the catalytic performance by fine-tuning structure of the support.

Design and regulation of defective electrocatalysts.

Electrocatalysts are the key components of electrochemical energy storage and conversion devices. High performance electrocatalysts can effectively reduce the energy barrier of the chemical reactions, thereby improving the conversion efficiency of energy devices. The electrocatalytic reaction mainly experiences adsorption and desorption of molecules (reactants, intermediates and products) on a catalyst surface, accompanied by charge transfer processes. Therefore, surface control of electrocatalysts plays a pivotal role in catalyst design and optimization. In recent years, many studies have revealed that the rational design and regulation of a defect structure can result in rearrangement of the atomic structure on the catalyst surface, thereby efficaciously promoting the electrocatalytic performance. However, the relationship between defects and catalytic properties still remains to be understood. In this review, the types of defects, synthesis methods and characterization techniques are comprehensively summarized, and then the intrinsic relationship between defects and electrocatalytic performance is discussed. Moreover, the application and development of defects are reviewed in detail. Finally, the challenges existing in defective electrocatalysts are summarized and prospected, and the future research direction is also suggested. We hope that this review will provide some principal guidance and reference for researchers engaged in defect and catalysis research, better help researchers understand the research status and development trends in the field of defects and catalysis, and expand the application of high-performance defective electrocatalysts to the field of electrocatalytic engineering.

A Thermostable Heme Protein Fold Adapted for Stereoselective C-H Bond Hydroxylation Using Peroxygenase Activity.

Thermostable protein folds of natural and synthetic origin are highly sought-after templates for biocatalyst generation due to their enhanced stability to elevated temperatures which overcomes one of the major limitations of applying enzymes for synthesis. Cytochrome P450 enzymes (CYPs) are a family of heme-thiolate monooxygenases that catalyse the oxidation of their substrates in a highly stereo- and regio-selective manner. The CYP enzyme (CYP107PQ1) from the thermophilic bacterium Meiothermus ruber binds the norisoprenoid β-ionone and was employed as a scaffold for catalyst design. The I-helix was modified to convert this enzyme from a monooxygenase into a peroxygenase (CYP107PQ1QE), enabling the enantioselective oxidation of β-ionone to (S)-4-hydroxy-β-ionone (94% e.e.). The enzyme was resistant to 20 mM H2O2, 20% (v/v) of organic solvent, supported over 1700 turnovers and was fully functional after incubation at 60 °C for 1 h and 30 °C for 365 days. The reaction was scaled-up to generate multi milligram quantities of the product for characterisation. Overall, we demonstrate that sourcing a CYP protein fold from an extremophile enabled the design of a highly stable enzyme for stereoselective C-H bond activation only using H2O2 as the oxidant, providing a viable strategy for future biocatalyst design.

Diverse effects of ferromagnetic-paramagnetic phase transition on the activity and selectivity of ferromagnetic catalysts

Tuning the catalyst’s activity and selectivity is usually achieved by modifying the electronic structure through strategies such as alloying, doping, strain, and ligand modification, but inevitably accompanied by geometric structure changes of catalysts. It is challenging to modify a catalyst’s electronic structure without changing its geometric structure. Recent studies found that the second-order ferromagnetic to paramagnetic (FM-PM) phase transition could promote catalytic performance without altering the geometric structures of active sites, which was also known as the magneto-catalytic effect (MCE). However, the understanding of the MCE is still incomplete. Herein, we conducted systematic density functional theory (DFT) calculations to clarify the complex reaction mechanisms for conversions of nitrogen-containing small molecules on both FM and PM Ni (111) surfaces. Our microkinetic modeling (MKM) results demonstrate that FM-PM phase transition promotes the N2O decomposition activity of FM Ni catalyst but decreases its activity for NO decomposition while showing a negligible influence on the activity of ammonia decomposition. These results indicate the promotion, inhibition, and disappearance mechanisms of MCE on the catalytic activity, which further changes the selectivity of different products. We anticipate the MCE will work as an effective strategy for fine-tuning the activity and selectivity of ferromagnetic catalysts in heterogeneous catalysis, providing an extra basis for rational catalyst design.

Lactonization of Diols Over Highly Efficient Metal-Based Catalysts.

Lactones has gained increasing attention in recent years due to wide application in polymer and pharmaceutical industries. Traditional synthetic methods of lactones often involve harsh operating temperature, use of strong alkalis and toxic oxidants. Therefore, lactonization of diols under milder conditions have been viewed as the most promising route for future commercialization. A variety of metal catalysts (Ru, Pt, Ir, Au, Fe, Cu, Co, and Zn) have been developed for highly efficient oxidant-, acceptor-, base- and additive-free lactonization processes. However, only a few initial attempts have been reported with no further details on catalytic mechanism being disclosed in literature. There demands a systematic study of the mechanistic details and the structure-function relationship to guide the catalyst design. In this work, we critically reviewed and discussed the structure-function relationship, the catalytic reaction mechanism, the catalyst stability, as well as the effect of oxidant and solvent for lactonization of diols. This work may provide additional insights for the development of other oxygen-containing functional molecules for material science and technologies.

Unraveling Lewis acid-base sites in defected MOFs for catalyzing dicyclopentadiene hydrogenation via a DFT study and descriptor exploration

The 12-connected UiO-66 MOFs with great defect regulation ability have attracted significant attention due to the easily tunable electronic structure and surface electrostatic potential distribution of metal nodes. In this density functional theory (DFT) study, we systematically explored the effect of bi-active site types as the frustrated Lewis pair (FLP) and classical Lewis pair (LP) as well as metal elements of secondary building units (SBUs) on the catalytic hydrogenation of dicyclopentadiene (DCPD) to tetrahydrodicyclopentadiene (THDCPD). These design strategies effectively modulate the frontier molecular orbital energy level that determines the binding strength between MOFs and adsorbed species *Hδ+-Hδ- and charges transfer before and after H2 chemisorption. We also found that the heterolytic H2 adsorption energy and charges transfer linearly correlate with the energy barrier. In order to unravel the clear-cut designing strategies and further simplify computational complexity, we firstly proposed the ADCH charges difference between the Lewis acid and the Lewis base centers (ΔQM-O) as an intrinsic descriptor for catalytic activity of DCPD into THDCPD, which can effectively describe the reactivity and electrostatic effects of oppositely charged bi-active sites in the system. Furthermore, the defective UiO-66(Ce) MOF with moderate ΔQM-O effectively balance the contradiction between the barriers of two primitive reaction: the heterolytically H2 dissociation to *Hδ+-*Hδ- and the desorption of the active hydrogen species to hydrogenate 8,9-dihydrodicyclopentadiene (8,9-DHDCPD), resulting in the optimal catalytic performance. This work provides a deep understanding of the catalytic mechanism of MOFs with multiple active sites and might open up avenues for the rational design of novel hydrogenation catalysts.

Remarkable Active Site Utilization in Edge-Hosted-N Doped Carbocatalysts for Fenton-Like Reaction.

Improving the utilization of active sites in carbon catalysts is significant for various catalytic reactions, but still challenging, mainly due to the lack of strategies for controllable introduction of active dopants. Herein, a novel "Ar plasma etching-NH3 annealing" strategy is developed to regulate the position of active N sites, while maintaining the same nitrogen species and contents. Theoretical and experimental results reveal that the edge-hosted-N doped carbon nanotubes (E-N-CNT), with only 0.29 at.% N content, show great affinity to peroxymonosulfate (PMS), and exhibit excellent Fenton-like activity by generating singlet oxygen (1O2), which can reach as high as 410 times higher than the pristine CNT. The remarkable utilization of edge-hosted nitrogen atom is further verified by the edge-hosted-N enriched carbocatalyst, which shows superior capability for 4-chlorophenol degradation with a turnover frequency (TOF) value as high as 3.82 min-1, and the impressive TOF value can even surpass those of single-atom catalysts. This work proposes a controllable position regulation of active sites to improve atom utilization, which provides a new insight into the design of excellent Fenton-like catalysts with remarkable atom utilization efficiency.

Understanding the Impact of Hydroxyls on Synthesizing the Bimetallic Alloy Pt3Co on Al2O3 for CO-PROX

The anchoring effect between surface hydroxyls (–OH) and metal species has been extensively utilized to enhance catalyst stability. Nevertheless, few studies have investigated the impact of alloying process involving different types of –OH species. In this research, we discovered that the formation of the alloy particles Pt3Co was significantly influenced by the presence of distinct –OH species on Al2O3. Intriguingly, those Pt3Co alloy particles exclusively formed on α-Al2O3 owing to the weak interaction between both Pt and Co species and the triply bridging hydroxyls (µ3-OH). In contrast, Pt and Co species were found to be separately dispersed on γ-Al2O3 because of the strong anchoring effect of terminal hydroxyls (µ1-OH), especially for Co atoms. Density functional theory (DFT) calculations highlighted the difference in adsorption energies of the two metals on different hydroxyl groups, providing a theoretical rationale for the influence of hydroxyl groups on alloy formation. The presence of Pt3Co alloy resulted in a fourfold increase in the specific catalytic rate of Pt3Co/α-Al2O3 in CO-PROX compared to Pt3Co/γ-Al2O3. Arguably for the first time, this study demonstrates the association between alloy formation and –OH groups, providing a unique perspective on the design of alloy catalysts.

Enhanced Photocatalytic Ozonation Using Modified TiO2 With Designed Nucleophilic and Electrophilic Sites.

Photocatalytic ozonation is considered to be a promising approach for the treatment of refractory organic pollutants, but the design of efficient catalyst remains a challenge. Surface modification provides a potential strategy to improve the activity of photocatalytic ozonation. In this work, density functional theory (DFT) calculations were first performed to check the interaction between O3 and TiO2-OH (surface hydroxylated TiO2) or TiO2-F (surface fluorinated TiO2), and the results suggest that TiO2-OH displays better O3 adsorption and activation than does TiO2-F, which is confirmed by experimental results. The surface hydroxyl groups greatly promote the O3 activation, which is beneficial for the generation of reactive oxygen species (ROS). Importantly, TiO2-OH displays better performance towards pollutants (such as berberine hydrochloride) removal than does TiO2-F and most reported ozonation photocatalysts. The total organic carbon (TOC) removal efficiency reaches 84.4 % within two hours. This work highlights the effect of surface hydroxylation on photocatalytic ozonation and provides ideas for the design of efficient photocatalytic ozonation catalysts.

Ultra-Narrow Alkane Product Distribution in Polyethylene Waste Hydrocracking by Zeolite Micropore Diffusion Optimization.

Plastic pollution poses a pressing environmental challenge in modern society. Chemical catalytic conversion offers a promising solution for upgrading waste plastics into valuable liquid alkanes and other high value products. However, the current methods yield mixed products with a broad carbon distribution. To address this challenge, we introduce a tandem catalytic system that features matched acidic sites and confined metals for the conversion of low-density polyethylene (LDPE) into liquid alkanes. This system achieves a liquid alkane yield of 94.0%, with 84.8% of C5-C7 light alkanes. Combined with in situ FTIR and molecular dynamics simulation, the shape-selective mechanisms is elucidated, which ensures that only olefins of the appropriate size can diffuse to the encapsulated Pt sites within the zeolite for hydrogenation, resulting in an ultra-narrow product distribution. Furthermore, due to the rapid diffusion of olefins within the hierarchical zeolite, the catalyst exhibits higher catalytic efficiency and resistance to coking tendency. Our findings contribute to the design of efficient catalysts for plastic waste valorization.

Hybrid Quantum Mechanical, Molecular Mechanical, and Machine Learning Potential for Computing Aqueous-Phase Adsorption Free Energies on Metal Surfaces.

Performing reliable computer simulations of elementary processes occurring at metal-water interfaces is pivotal for novel catalyst design in sustainable energy applications. Computational catalyst design hinges on the ability to reliably and efficiently compute the potential energy surface (PES) of the system. Due to the large system sizes needed for studying processes at liquid water-metal interfaces, these systems can currently not be described using density functional theory (DFT). In this work, we used a hybrid quantum mechanical, molecular mechanical, and machine learning potential for studying the adsorption behavior of phenol, atomic hydrogen, 2-butanol, and 2-butanone on the (0001) facet of Ru under reducing conditions when Ru is not oxidized. Specifically, we describe the adsorbate and the surrounding metal atoms at the DFT level of theory. Here, we also considered the electrostatic field effect of the water molecules on adsorbate-metal interactions. Next, for the water-water and water-adsorbate interactions, we used established classical force fields. Finally, for the water-Ru surface interaction, for which no reliable force fields have been published, we used Behler-Parrinello high-dimensional neural network potentials (HDNNPs). Employing this setup, we used our explicit solvation for metal surface (eSMS) approach to compute the aqueous-phase effect on the low-coverage adsorption of selected molecules and atoms on the (0001) facet of Ru. In agreement with previous experimental and computational studies of oxygenated molecules over transition metal facets, we found that liquid water destabilizes the tested adsorbates on Ru(0001). Interestingly, our findings indicate that adsorbates on Ru are less affected by the presence of an aqueous phase than on other transition metals (e.g., Pt), highlighting the necessity of experimental investigations of Ru-based catalytic systems in liquid water.

Unraveling high-temperature mechanism of NO + CO reaction on BaO-Y2O3: An in situ DRIFTS and microkinetic study

Understanding high-temperature mechanism of NO reduction by CO on heat-resistant metal oxides is crucial for exhaust aftertreatment systems. We employed the NO + CO light off experiment, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), density functional theory (DFT), and microkinetic study to elucidate the reaction mechanism on BaO-Y2O3 nanocatalyst. The catalytic cycle consisting of “decomposition-oxidation” mode, Mars-van Krevelen (MvK) mechanism, and Langmuir-Hinshelwood (L-H) mechanism is described by in situ DRIFTS and DFT calculations. Their reaction energies and activation barriers are then employed for the microkinetic analysis, revealing that the activity rate is temperature-dependent and aligns with the experimental result. The high-temperature reaction process is primarily governed by the MvK mechanism with rate-determining steps (RDS) of CO + OL ↔ CO2 + Ov, followed by the “decomposition-oxidation” mode. Critically, local CO32- coverage on the BaO surface can facilitate NO and CO adsorption while withstanding the elementary steps such as N2O dissociation and CO oxidation by lattice oxygen. BaCO3-Y2O3 model can be used to interpret the low-temperature reaction process with the RDS of N2O2 ↔ N2O + O, but it impedes reaction kinetics at high temperatures with the rate contribution also predominantly originating from the MvK mechanism. This work provides fundamental insights into how the reaction proceed, and guide the design and optimization of catalysts that can withstand high temperature while maintaining high activity.

Regulation mechanism of wavy β12 borophene-supported dual-atom catalysts on ethanol product

Improving CO2RR electrocatalysis is vital for meeting growing energy demands. Dual-atom catalysts (DACs) show promise, with activity tunable via stress-responsive substrates. Highly flexible borophene, exhibiting periodic undulations under stress, emerges as an attractive DAC substrate. Despite potential, wave-like DACs for C2 production remain unexplored due to modeling complexities and unknown intermediates. We present wave-like borophene anchored with Cu atoms, studied via density functional theory, revealing synergistic effects and surface restructuring mechanisms in C2 reactions. Stressing borophene reduces ethanol reduction overpotential (from 0.75 V to 0.60 V) and enhances interfacial interactions. This work highlights the potential of stress-modulated substrates in advancing efficient alcohol conversion strategies, paving the way for the innovative design and optimization of dual-atom catalysts (DACs).

Regulating N-Cu/MoxC interfacial effect coupling β-Mo2C/γ-MoC phase engineering to achieve efficient hydrolysis dissociation and methanol dehydrogenation for hydrogen production

Methanol steam reforming (MSR) is a promising solution for achieving the integration of hydrogen storage, transportation, and in-situ supply. However, it is limited by the slow rate of hydrogen generation and low selectivity. This study constructed a highly active N-Cu/MoxC catalyst with strong interaction between Cu and MoxC, effectively enhancing methanol activation, hydrolysis, and hydrogen production efficiency. Under optimized condition, the 2.8 N-Cu/MoxC catalyst achieved a remarkable H2 productivity of 147.9 mmol gcat−1 h−1 and H2 selectivity of 65.7 %. N induced a partial transition from β-Mo2C phase to γ-MoC phase, resulting in a doubling of H2 production rate. The interfacial N-Cu-MoxC sites facilitated highly reactive efficient CH bond dissociation to convert CO+4H and OH activation, as well as the highly efficient CO reforming. Additionally, temperature programmed surface reaction and isotope testing futher coroborated its superiority in methanol dehydrogenation and hydrolysis dissociation. These discoveries can provide guidance for the design of advanced MSR catalysts.

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis.

Organocatalysis has established itself as a third pillar of homogeneous catalysis, besides transition metal catalysis and biocatalysis, as its use for enantioselective reactions has gathered significant interest over the last decades. Concurrent to this development, machine learning (ML) has been increasingly applied in the chemical domain to efficiently uncover hidden patterns in data and accelerate scientific discovery. While the uptake of ML in organocatalysis has been comparably slow, the last two decades have showed an increased interest from the community. This review gives an overview of the work in the field of ML in organocatalysis. The review starts by giving a short primer on ML for experimental chemists, before discussing its application for predicting the selectivity of organocatalytic transformations. Subsequently, we review ML employed for privileged catalysts, before focusing on its application for catalyst and reaction design. Concluding, we give our view on current challenges and future directions for this field, drawing inspiration from the application of ML to other scientific domains.