Despite the fact that the methanol synthesis process includes industrially some of the most important catalytic chemical reactions, it is still not clear how different gaseous species impact catalyst component structure. With the goal to reduce CO2 emissions through hydrogenation to CH3OH, a higher H2O formation rate than in the production from compressed CO-rich feed should also be considered. It is known that steam accelerates the sintering of metals, several oxide compounds, and their interfaces. To determine the effect of moisture on the Cu/ZnO/Al2O3 catalysts, a commercial catalytic material was systematically aged at various gas compositions and analyzed using transient H2 surface adsorption, N2O pulse efficient chemisorption, X-ray photoelectron spectroscopy, scanning transmission electron microscopy mapping, X-ray powder diffraction, and N2 physisorption, and the mechanisms of deactivation were observed. A strong consistent relation between the compacting of Al2O3, the amount of water in the controlled streamflow, and the activity was found. This connected loss of support resulted in the (re)­forming of Cu, ZnO, and Cu/ZnO phases. Copper particle growth was modeled by applying a physical coalescence model. In the presence of CO and/or CH3OH, zinc oxide material started to cover the Cu granules, while H2O promoted the development of separate Cu regions.

Selective catalytic reduction of CO 2 to methanol has tremendous importance in the chemical industry. It mitigates two critical issues in the modern society, the overwhelming climate change and the dependence on fossil fuels. The most used catalysts are currently based on mixed copper and zinc phases, where the high surface of active copper species is a critical factor for the catalyst performance. Motivated by the recent breakthrough in the controllable synthesis of bimetallic MOF-74 materials by ball milling, we targeted to study the potential of ZnCu-MOF-74 for catalytic CO 2 reduction. Here, we tested whether the nanosized channels decorated with readily accessible and homogeneously distributed Zn and Cu metal sites would be advantageous for the catalytic CO 2 reduction. Unlike the inactive monometallic Cu-MOF-74, ZnCu-MOF-74 shows moderate catalytic activity and selectivity for the methanol synthesis. Interestingly, the postsynthetic mechanochemical treatment of desolvated ZnCu-MOF-74 resulted in amorphization and a significant increase in both the activity and selectivity of the catalyst despite the destruction of the well-ordered and porous MOF-74 architecture. The results emphasize the importance of defects for the MOF catalytic activity and the potential of amorphous MOFs to be considered as heterogeneous catalysts. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and 13 C magic angle-spinning nuclear magnetic resonance (MAS NMR) were applied to establish quantitative structure− reactivity relationships. The apparent activation energy of rate reaction kinetics has indicated different pathway mechanisms, primarily through reverse water−gas shift (RWGS). Prolonged time on stream productivity, stability and deactivation were assessed, analysing the robustness or degradation of metal−organic framework nanomaterials. Scalable MOF production processes are making the latter more appealing within emerging industrial decarbonisation, in particular for carbon capture and utilisation (CCU) or hydrogen carrier storage. Acknowledging scale, the costs of fabrication are paramount.

A holistically described radical-induced redox chemistry modelling allows for a direct assessment of the in situ experiments inside a liquid-cell TEM.

There has been a growing trend to couple different levels of modelling, such as going from first-principle calculations to the meso (e.g. kinetic Monte Carlo-KMC) and macro scale (e.g. computational fluid dynamics-CFD). In the current investigation, we put forward a CFD study of CO 2 hydrogenation to methanol for heterogeneous reacting flows in reactors with complex shape geometries, coupled with first-principle calculations (density functional theory (DFT)). KMC operation simulations were also performed to obtain insight into the uppermost layer conditions during the reaction. With computational fluid dynamics, the focus was placed on the non-uniform catalytic reduction of carbon dioxide to formate, which we treated with a detailed mean-field first-principle microkinetic model, analysed, and corroborated with experiments. The results showed a good consistent agreement with experimental data. The formulated methodological approach paves the way towards full virtual multiscale system descriptions of industrial processing units, encompassing all conventional stages, from catalyst design to the optimisation of mass transfer parameters. Such a bridging is outlined for carbon capture and utilisation.

As one of the most demanded dicarboxylic acids, adipic acid can be directly produced from renewable sources. Hexoses from (hemi)cellulose are oxidized to aldaric acids and subsequently catalytically dehydroxylated. Hitherto performed homogeneously, we present the first heterogeneous catalytic process for converting an aldaric acid into muconic and adipic acid. The contribution of leached Re from the solid prereduced catalyst was also investigated with hot-filtration test and found to be inactive for dehydroxylation. Corrosive or hazardous (HBr/H 2) reagents are avoided and simple alcohols and solid Re/C catalysts in an inert atmosphere are used. At 120 8C, the carboxylic groups are protected by esterification, which prevents lactonization in the absence of water or acidic sites. Dehydroxylation and partial hydrogenation yield monohexenoates (93 %). For complete hydrogenation to adipate, a 16 % higher activation barrier necessitates higher temperatures.