Methanol, an important chemical, fuel additive, and precursor for clean fuels, is produced by hydrogenation of carbon oxides over Cu‐based catalysts. Despite the technological maturity of this process, the understanding of this apparently simple reaction is still incomplete with regard to the reaction mechanism and the active sites. Regarding the latter, recent progress has shown that stepped and ZnOx‐decorated Cu surfaces are crucial for the performance of industrial catalysts. Herein, we integrate this insight with additional experiments into a full microkinetic description of methanol synthesis. In particular, we show how the presence or absence of the Zn promoter dramatically changes not only the activity, but unexpectedly the reaction mechanism itself. The Janus‐faced character of Cu with two different sites for methanol synthesis, Zn‐promoted and unpromoted, resolves the long‐standing controversy regarding the Cu/Zn synergy and adds methanol synthesis to the few major industrial catalytic processes that are described on an atomic level.

We report on the activation of CO 2 on Ni single-atom catalysts. These catalysts were synthesized using a solid solution approach by controlled substitution of 1–10 atom % of Mg 2+ by Ni 2+ inside the MgO structure. The Ni atoms are preferentially located on the surface of the MgO and, as predicted by hybrid-functional calculations, favor low-coordinated sites. The isolated Ni atoms are active for CO 2 conversion through the reverse water–gas shift (rWGS) but are unable to conduct its further hydrogenation to CH 4 (or MeOH), for which Ni clusters are needed. The CO formation rates correlate linearly with the concentration of Ni on the surface evidenced by XPS and microcalorimetry. The calculations show that the substitution of Mg atoms by Ni atoms on the surface of the oxide structure reduces the strength of the CO 2 binding at low-coordinated sites and also promotes H 2 dissociation. Astonishingly, the single-atom catalysts stayed stable over 100 h on stream, after which no clusters or particle formation could be detected. Upon catalysis, a surface carbonate adsorbate-layer was formed, of which the decompositions appear to be directly linked to the aggregation of Ni. This study on atomically dispersed Ni species brings new fundamental understanding of Ni active sites for reactions involving CO 2 and clearly evidence the limits of single-atom catalysis for complex reactions.

We report the application of an optimised synthesis protocol of a Cu/ZnO:Al catalyst. The different stages of synthesis are all well-characterised by using various methods with regard to the (micro-)structural, textural, solid-state kinetic, defect and surface properties. The low amount of the Al promoter (3 %) influences but does not generally change the phase evolution known for binary Cu/ZnO catalysts. Its main function seems to be the introduction of defect sites in ZnO by doping. These sites as well as the large Cu surface area are responsible for the large N₂O chemisorption capacity. Under reducing conditions, the Al promoter, just as Zn, is found enriched at the surface suggesting an active role in the strong metal–support interaction between Cu and ZnO:Al. The different stages of the synthesis are comprehensively analysed and found to be highly reproducible in the 100 g scale. The resulting catalyst is characterised by a uniform elemental distribution, small Cu particles (8 nm), a porous texture (pore size of approximately 25 nm), high specific surface area (approximately 120 m²  g^-1), a high amount of defects in the Cu phase and synergetic Cu–ZnO interaction. A high and stable performance was found in methanol synthesis. We wish to establish this complex but well-studied material as a benchmark system for Cu-based catalysts

The “Seven Pillars” of oxidation catalysis proposed by Robert K. Grasselli represent an early example of phenomenological descriptors in the field of heterogeneous catalysis. Major advances in the theoretical description of catalytic reactions have been achieved in recent years and new catalysts are predicted today by using computational methods. To tackle the immense complexity of high-performance systems in reactions where selectivity is a major issue, analysis of scientific data by artificial intelligence and data science provides new opportunities for achieving improved understanding. Modern data analytics require data of highest quality and sufficient diversity. Existing data, however, frequently do not comply with these constraints. Therefore, new concepts of data generation and management are needed. Herein we present a basic approach in defining best practice procedures of measuring consistent data sets in heterogeneous catalysis using “handbooks”. Selective oxidation of short-chain alkanes over mixed metal oxide catalysts was selected as an example.

The efficient conversion of CO 2 into various chemicals and fuels is a prospective building block for the more sustainable use of our global resources. [1] Among the various strategies that have been proposed for converting CO 2 into higherenergy intermediates, [2] processes that employ heterogeneous catalysis are of special interest, because they are scalable, based on a mature and flexible technology that has already been applied in the chemical industry, and can be integrated into existing value chains. [3] The dry reforming of methane (DRM) with carbon dioxide is an interesting method for converting these two greenhouse gases into CO/H 2 mixtures [Eq. (1)]. This reaction opens the door to utilizing anthropogenic CO 2 , which is obtained from, for example, oxy-fuel-combustion processes, in the well-established downstream chemistry of syngas to afford MeOH and other base chemicals or fuels through Fischer-Tropsch synthesis.The highly endothermic DRM reaction has long been studied as a potential alternative for the steam reforming of methane and several comprehensive reviews have been published on this topic. [4][5][6] It is well-known that Ru, Rh, and Pt catalysts are very active in this reaction. Active base metals-and Ni in particular-suffer from fast deactivation by coking. [7,8] However, from an economic point of view, Ni-based catalysts are more suitable for commercial applications than noble-metal ones. Thus, a current challenge is to find a noble-metal-free catalyst that is resistant towards coking. [9] Promising approaches in the literature include the poisoning of coke-forming sites by sulfur, [10] variation of the support, [11] in particular through the application of Lewis-basic materials, [12] the addition of alkaline or alkaline-earth oxides as promoters, [13][14] and the incorporation of Ni into a perovskite framework. [15] It has been shown that the deposition of carbon over Ni at 700 8C and over Rh at 750 8C originates from the exothermic Boudouard reaction [Eq. (2)] and not primarily from methane decomposition [Eq. (3)]. [16,17] 2 CO $ CO 2 þC DH 298 ¼ À172 kJ mol À1 ð2ÞThus, the process temperature is an important parameter in the DRM reaction. [4] Considering the thermodynamics of the desired endothermic DRM and of the undesired exothermic Boudouard reaction, a promising way of suppressing coking would be to perform the DRM reaction at high temperatures. [18] Typically, 750 8C is an upper limit in many literature reports. In addition, the thermodynamic yields of CO and H 2 would increase at higher temperatures. Following this concept, the primary challenge in making the Ni particles kinetically more resistant to coking involves making a large Ni surface area thermally stable against sintering at more elevated temperatures. Herein, we report the synthesis, characterization andThe catalytic performance of a Ni/MgAlO x catalyst was investigated in the high temperature CO 2 reforming of CH 4 . The catalyst was developed using a Ni, Mg, Al hydrotalcite-like precursor obtained by co-precipitation. ...