The lack of machine-readable experimental data impedes data-driven discoveries in catalysis research. To advance the FAIR principles — guidelines to improve the Findability, Accessibility, Interoperability and Reuse of digital assets — we have developed a catalysis plugin (called the Catalysis App) for the NOMAD platform that supports standardized data upload and features integrated visualization. This infrastructure provides a robust foundation for machine-learning workflows and the direct comparison of experimental data with theory.

Single-atom alloys have recently emerged as highly active and selective alloy catalysts. Unlike pure metals, single-atom alloys escape the well-established conceptual framework developed nearly three decades ago for predicting catalytic performance. Although this offers the opportunity to explore so far unattainable chemistries, this leaves us without a simple guide for the design of single-atom alloys able to catalyse targeted reactions. Here, based on thousands of density functional theory calculations, we reveal a 10-electron count rule for the binding of adsorbates on the dopant atoms, usually the active sites, of single-atom alloy surfaces. A simple molecular orbital approach rationalizes this rule and the nature of the adsorbate–dopant interaction. In addition, our intuitive model can accelerate the rational design of single-atom alloy catalysts. Indeed, we illustrate how the unique insights provided by the electron count rule help identify the most promising dopant for an industrially relevant hydrogenation reaction, thereby reducing the number of potential materials by more than one order of magnitude.

Findable, Accessible, Interoperable, and Reusable (FAIR) data is currently emerging as an indispensable element in the advancement of science and requires the development of new methods for data acquisition, storage and sharing. This is becoming even more critical as the increasing application of artificial intelligence demands significantly higher data quality in terms of reliability, reproducibility and consistency of datasets. This paper presents methods for the digital and automatic acquisition and storage of data and metadata in catalysis experiments based on open-source software solutions. The successful implementation of a digitalization concept, which includes working according to machine-readable standardized operating procedures (SOPs) is outlined using a reactor for catalytic tests that has been automated with the open-source software tool EPICS (Experimental Physics and Industrial Control System). The process of data acquisition, standardized analysis, upload to a database and generation of relationships between database entries is fully automated. Application programming interfaces (APIs) have been developed to enable data exchange within the local data infrastructure and beyond to overarching repositories, paving the way for autonomous catalyst discovery and machine learning applications.

Bringing molecules together on a catalytic surface is a prerequisite for bimolecular and recombination reactions. However, in the absence of attractive interactions between reactants, such as hydrogen bonds, this poses a challenge. In contrast, based on density functional theory, we show that coadsorption at active sites of single-atom alloys (SAAs) is favored and that coadsorption is a general phenomenon observed for catalytically relevant adsorbates on a broad range of SAAs under temperature and pressure conditions commonly employed for catalysis. Dopants located in both terrace sites and in step edge defects exhibit a preference for coadsorption, displaying similar periodic trends. Using kinetic Monte Carlo simulations, we compare the reactivity of a model reaction on both a pure metal and an SAA and show that the preference for coadsorption significantly alters the overall reaction energy profile, even when the barriers for the rate-determining elementary step are identical. In our models, the coadsorption preference enhances the catalytic activity of the SAA surface by several orders of magnitude compared to the pure metal. We also report infrared (IR) spectroscopic signatures of coadsorption, which facilitate experimental detection. Analysis reveals that in these systems repulsive lateral interactions between nearby molecules are more than compensated for by the enhanced binding at dopant sites. Among the broad range of systems considered, SAAs containing early transition metals (TMs) exhibit the strongest coadsorption preference, which can be rationalized by assuming the existence of an optimal number of electrons involved in binding. The strong coadsorption preference, together with facile product desorption from early TMs, renders these systems attractive candidates for catalysis. Moreover, these SAAs could open new routes for reduction reactions because coadsorption with hydrogen is favored.

Heterogeneous catalysis is an important area of research that generates data as intricate as the phenomenon itself. Complexity is inherently coupled to the function of the catalyst and advance in knowledge can only be achieved if this complexity is adequately captured and accounted for. This requires integration of experiment and theory, high data quality and quality control, close interdisciplinary collaboration, and sharing of data and metadata, which is facilitated by the application of joint data management strategies. This Viewpoint Article first discusses the potential of a digital transition in catalysis research. Then, a summary of the current status in terms of data infrastructure in heterogeneous catalysis is presented, defining the various types of (meta-) data, from catalyst synthesis to functional analysis. Finally, an already implemented working concept for local data acquisition and storage is introduced and the benefits and further development directions for catalysis data use and sharing are discussed.

This invited Team Profile was created by a group of scientists working on concepts for research data management in catalysis in the Department of Inorganic Chemistry at the Fritz-Haber-Institut (FHI) der Max-Planck-Gesellschaft in Berlin. They recently published an article about their views on the ongoing digital transformation in catalysis research, in which the structure and current status of catalysis data are analyzed to highlight the benefits of FAIR data. Considering the fundamental aspects of catalysis as a kinetic phenomenon, they discuss how working methods should change to achieve a deeper understanding of the physical principles governing catalysis and discover new catalysts. "Achieving Digital Catalysis: Strategies for Data Acquisition, Storage and Use"

There is widespread interest in developing catalysts with uniform active sites that consist of single atoms, thereby simplifying the reaction mechanism and improving product selectivity. We examine experimentally how CO can be used to modify the active sites on a strong binding single-atom alloy and examine how this in turn impacts product selectivity for a reaction that has two different pathways. Specifically, we find that CO can be used to selectively block isolated Rh atom active sites in a RhCu(111) model single-atom alloy catalyst surface and promote the dehydrogenation pathway for adsorbed ethyl groups by suppressing the hydrogenation pathway.

Single-Atom Alloys (SAAs) have recently emerged as highly active and selective alloy catalysts. Unlike pure metals, SAAs escape the well-established conceptual framework developed nearly three decades ago for predicting catalytic performance. Here, based on high throughput density functional theory calculations, we reveal a 10-electron count rule for the binding of adsorbates on the dopant of SAA surfaces. A simple molecular orbital approach rationalises this rule and the nature of the adsorbate/dopant interaction. In addition, our intuitive model can accelerate the rational design of SAA catalysts. Indeed, we illustrate how the unique insights provided by the electron count rule help identify the most promising dopant for an industrially relevant hydrogenation reaction, thereby reducing the number of potential materials by more than one order of magnitude.

Dicarbonyl species are ubiquitous on Rh/oxide catalysts and are known to form on Rh+ centers. However, dicarbonyl species have never been directly observed on single-atom alloys (SAAs) where the active site is metallic. Herein, using surface science and theoretical modeling, we provide evidence of dicarbonyl species at isolated Rh sites on a RhCu(100) SAA. This approach not only enables us to directly visualize dicarbonyl species at Rh sites but also demonstrates that the transition between the mono- and dicarbonyl configuration can be achieved by changing surface temperature and CO pressure. Density functional theory calculations further support the mono- and dicarbonyl assignments and provide evidence that these species should be stable on other SAA combinations. Together, these results provide a picture of the structure and energetics of both the mono- and dicarbonyl configurations on the RhCu(100) SAA surface and should aid with IR assignments on SAA nanoparticle catalysts.

The reaction of a borylnitrene with carbon dioxide is studied under cryogenic matrix isolation conditions. Photogenerated CatBN (Cat=catecholato) reacts with CO2 under formation of the cycloaddition product CatBNCO2 , a 3-oxaziridinone derivative, after photoexcitation (>550 nm). The product shows Fermi resonances between the CO stretching and ring deformation modes that cause unusual 13 C and 18 O isotopic shifts. A computational analysis of the 3-oxaziridinone shows this cyclic carbamate to be less strained than an α-lactone or an α-lactame.

Rhodium atoms for alkane dehydrogenation Nanoparticles of rhodium dispersed on metal oxides are generally poor catalysts for alkane dehydrogenation because the reactants bind too strongly to the metal. Hannagan et al. performed first-principle calculations indicating that single rhodium atoms in a copper surface should be stable and selective for conversion of propane to propene and hydrogen. Model studies of single rhodium atoms embedded in a copper (111) surface revealed a very high selectivity to propene and high resistance to the formation of surface carbon that would deactivate the catalyst. Science , abg8389, this issue p. 1444

Single-atom alloys (SAAs) make up a special class of alloy surface catalysts that offer well-defined, isolated active sites in a more inert metal host. The dopant sites are generally assumed to have little or no influence on the properties of the host metal, and transport of chemical reactants and products to and from the dopant sites is generally assumed to be facile. Here, by performing density functional theory calculations and surface science experiments, we identify a new physical effect on SAA surfaces, whereby adsorption is destabilized by ≤300 meV on host sites within the perimeter of the reactive dopant site. We identify periodic trends for this behavior and demonstrate a zone of exclusion around the reactive sites for a range of adsorbates and combinations of host and dopant metals. Experiments confirm an increased barrier for diffusion of CO toward the dopant on a RhCu SAA. This effect offers new possibilities for understanding and designing active sites with tunable energetic landscapes surrounding them.

Recent developments in computational catalysis have allowed the routine reduction of the dimensionality of complex reaction networks to a few descriptors based on linear scaling relations. Despite this convenient benefit, linear scaling relations fundamentally limit the activity and selectivity of a given class of materials towards a given reaction. Here, we show an example by offering a novel description of the fundamental limits on the activity of CO hydrogenation to methanol; a reaction that offers a sustainable route to obtaining value-added chemicals from syngas. First, we show that there is a strong linear correlation between the formation energy of CO* (where * denotes an adsorbed species) and those of the transition states of a number of elementary steps along the methanol synthesis pathway on these surfaces. Using microkinetic modeling, we cast this information into activity volcano plots with the formation energies of a given transition state and CO* as independent descriptors. This analysis reveals the fundamental limits on activity imposed by the aforementioned linear scaling relations, and invites a vigorous search for novel materials that escape these linear scaling relations as a necessary condition for achieving improved activity towards methanol from CO hydrogenation. Specifically, we point out the transition states H–CO* and CH3O–H* as key transition states to be stabilized independently of CO* for improved activity and selectivity towards methanol synthesis.

The reaction of dioxygen with nitrenes can have significant energy barriers, although both reactants are triplet diradicals and the formation of nitroso-O-oxides is spin-allowed. By means of matrix-isolation infrared spectroscopy in solid argon, nitrogen, and neon, and through high-level computational quantum chemistry, it is shown herein that a 3-nitreno-1,3,2-benzodioxaborole CatBN (Cat=catecholato) reacts with dioxygen under cryogenic conditions thermally at temperatures as low as 7 K to produce two distinct products, ananti-nitroso-O-oxide and a nitritoborane CatBONO. The computed barriers for the formation of nitroso-O-oxide isomers are very low. Whereasanti-nitroso-O-oxide is kinetically trapped, its bisected isomer has a very low barrier for metathesis, yielding the CatBO+NO radicals in a strongly exothermic reaction; these radicals can combine under matrix-isolation conditions to give nitritoborane CatBONO. The trapped isomer,anti-nitroso-O-oxide, can form the nitritoborane CatBONO only after photoexcitation, possibly involving isomerization to the bisected isomer ofanti-nitroso-O-oxide.

Controlling selectivity is a key goal in the design of a heterogeneous catalyst. Herein, we present detailed characterization and activity of silica-supported cobalt catalysts modified by atomic layer deposition of ZnO. After reduction, the resulting catalysts exhibit substantial selectivity towards alcohol production during CO hydrogenation compared to catalysts containing only cobalt. The prepared catalysts have up to 46% selectivity toward alcohols with 39% of the alcohols corresponding to ethanol and other higher alcohols, albeit with reduced activity. In situ characterization of the catalyst by X-ray diffraction and X-ray absorption spectroscopy reveals details on the structural evolution in syngas, CO+H-2, and shows that ZnO promotion of Co results in the formation of Co2C under catalytic conditions. A mechanism is proposed, supported by density functional theory calculations, which explains Co2C formation by the blocking of Co step sites by Zn species. The ZnO acts a dual promoter both by facilitating Co2C formation and by modifying the resulting Co2C. The Co2C formed from the ZnO-promoted Co catalysts displays improved thermal stability and selectivity compared with similar Co2C catalysts without Zn.

In2O3 has recently emerged as a promising catalyst for methanol synthesis from CO2. In this work, we present the promotional effect of Pd on this catalyst and investigate structure-performance relationships using in situ X-ray spectroscopy, ex situ characterization, and microkinetic modeling. Catalysts were synthesized with varying In:Pd ratios (1:0, 2:1, 1:1, 1:2, 0:1) and tested for methanol synthesis from CO2/H-2 at 40 bar and 300 degrees C. In:Pd(2:1)/SiO2 shows the highest activity (5.1 mu mol MeOH/g(Inpd)s) and selectivity toward methanol (61%). While all bimetallic catalysts had enhanced catalytic performance, characterization reveals methanol synthesis was maximized when the catalyst contained both In-Pd intermetallic compounds and an indium oxide phase. Experimental results and density functional theory suggest the active phase arises from a synergy between the indium oxide phase and a bimetallic In-Pd particle with a surface enrichment of indium. We show that the promotion observed in the In-Pd system is extendable to non precious metal containing binary systems, in particular In-Ni, which displayed similar composition-activity trends to the In-Pd system. Both palladium and nickel were found to form bimetallic catalysts with enhanced methanol activity and selectivity relative to that of indium oxide.

DFT calculations are performed with the plane-wave based Quantum ESPRESSO code. [1] We employ the generalized-gradient approximation applying the van der Waals corrected exchange-correlation functional BEEF-vdW. [2] The interaction between the atomic cores and electrons is described by the projector augmented wave (PAW) method. [3,4] The Brillouin zone is sampled using a Monkhorst-Pack [5] mesh of 4 × 4 × 1 k points. The valence wave functions are expanded in a plane-wave basis with a cutoff energy of 500 eV. A four layer (3 × 3) fcc (111) slab is used in the calculations with the top two layers allowed to relax during the geometric optimizations until the force on each atom is less than 0.05 eV/ ˚A. Transition states (TS) of the reactions are determined by applying the climbing image nudged elastic band method [6] with five images used to form a discrete approximation of the path between fixed end points. The TS structures obtained in this way are further refined until the forces on atomic centers reach 0.05 eV/ ˚A. Gas phase energies were corrected using the correction scheme as suggested by Christensen et al. [7] that is 0.1 eV per H 2 molecule and 0.15 eV for the C=O bond in CH 3 CHO gas. Zero point energies and entropic contri-butions were calculated within the harmonic approximation. [8] Spurious frequencies that are smaller than 12 cm − 1 and imaginary frequencies smaller 100 cm − 1 associated with rotations or translational motions were replaced by 12 cm − 1 . This value is chosen as the entropy contribution from a pseudo-translational/rotational degree of freedom, as discussed in detail elsewhere. [9,10] Free energy corrections of gas-phase species were obtained using the

Using a combined density functional theory and descriptor based microkinetic model approach, we predict production rate volcanos for higher oxygenate formation on (111) transition-metal surfaces. Despite their lower activity for CO conversion compared to stepped surfaces, (111) transition metal surfaces bring the potential for selectivity toward C2+ oxygenates. The volcano plots can be used to rationalize and predict activity and selectivity trends for transition-metal-based catalysts.

Methanol is an important chemical compound which is used both as a fuel and as a platform molecule in chemical production. Synthesizing methanol, as well as dimethyl ether, directly from carbon dioxide and hydrogen produced using renewable electricity would be a major step forward in enabling an environmentally sustainable economy. We utilize density functional theory combined with microkinetic modeling to understand the methanol synthesis reaction mechanism on a model CoGa catalyst. A series of catalysts with varying Ga content are synthesized and experimentally tested for catalytic performance. The performance of these catalysts is sensitive to the Co:Ga ratio, whereby increased Ga content results in increased methanol and dimethyl ether selectivity and increased Co content results in increased selectivity towards methane. We find that the most active catalysts have up to 95% CO-free selectivity towards methanol and dimethyl ether during CO2 hydrogenation and are comparable in performance to a commercial CuZn catalyst. Using in situ DRIFTS we experimentally verify the presence of a surface formate intermediate during CO2 hydrogenation in support of our theoretical calculations.