Abstract:We report here the synthesis and testing of a set of 48 alumina-supported catalysts for hydrogenation of 5-ethoxymethylfurfural. This catalytic reaction is very important in the context of converting biomass to biofuels. The catalysts are composed of one main metal (gold, copper, iridium, nickel, palladium, platinum, rhodium, ruthenium) and one promoter metal (bismuth, chromium, iron, sodium, tin, tungsten). Using a 16-parallel trickle-flow reactor, we tested all 48 catalyst combinations under a variety of conditions. The results show that both substrate conversion and product selectivity are sensitive towards temperature changes and solvent effects. The best results of > 99% yield to the desired product, 5-ethoxymethylfurfuryl alcohol, are obtained using an iridium/chromium (Ir/Cr) catalyst. The mechanistic implications of different possible reaction pathways in this complex hydrogenation system are discussed.

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This document contains the detailed experimental results, additional information on the models reported in the main text and information required to reproduce the reported models. Specifically, all measured adsorption terms are given, the detailed equations of the obtained models, a separate set of models for hydrogen and hydroxyl radical and details on the specific variables and applications included in each model are provided. The additional information provided for the modeling results are sufficient to provide the reader with the means to reproduce any model reported in the main text.

We report new experimental results on the hydrogenation of 5-ethoxymethylfurfural, an important intermediate in the conversion of sugars to industrial chemicals, using eight different M/Al 2 O 3 catalysts (M = Au, Cu, Ni, Ir, Pd, Pt, Rh, and Ru) under various conditions. These data are then compared with the results for 48 bimetallic supported catalysts. The results are explained using a simple and effective model, applying catalyst descriptors based on Slater type orbitals (STOs). Each metal is described using four parameters: the height of the orbital peak, the distance of the peak from the metal atom centre, the peak width at half height, and the peak skewness. Importantly, all these parameters are derived from one simple equation, so the calculation is fast and robust. We then apply these descriptors for modeling the hydrogenation data using multivariate methods. Despite the inherent complexity of the reaction network, these simple models describe the catalysts' performance well. The general application of such descriptor models to in silico design and performance prediction of solid catalysts is discussed.

Catalytic conversion of biomass is a key challenge that we chemists face in the twenty-first century. Worldwide, research is conducted into obtaining bulk chemicals, polymers and fuels. Our project centres on glucose valorisation via furfural derivatives using catalytic hydrogenation. We present here new results for a set of 48 bimetallic catalysts supported on silica, and demonstrate the application of data mining tools to identify major trends in the data. These results are combined with a full factorial data set for the hydrogenation of 5-ethoxymethylfurfural over alumina-supported transition metal catalysts. All the catalysts in the combined datasets were synthesized and tested for performance under identical conditions. This, combined with the fact that no combinations of metals were left out, enables the use of advanced data mining tools. The paper describes the data and highlights the relevant trends from a chemist's viewpoint.

We report on an inverse model Cu/MgO methanol catalyst modified with 5 % zinc oxide at the Cu surface to element‐specifically probe the interplay of metallic copper and zinc oxide during reductive activation. The structure of copper and zinc was unraveled by in situ X‐ray diffraction (XRD) and in situ X‐ray absorption spectroscopy (XAS) supported by theoretical modelling of the extended X‐ray absorption fine structure and X‐ray absorption near‐edge structure spectra. Temperature‐programmed reduction in H2 during in situ XAS showed that copper was reduced starting at 145 °C. With increasing reduction temperature, zinc underwent first a geometrical change in its structure, followed by reduction. The reduced zinc species were identified as surface alloy sites, which coexisted from 200 °C to 340 °C with ZnO species at the copper surface. At 400 °C Zn−Cu bulk‐alloyed particles were formed. According to in situ XRD and in situ XAS, about half of the ZnO was not fully reduced, which can be explained by a lack of contact with copper. Our experimental results were further substantiated by density functional theory calculations, which verified that ZnO with neighboring Cu atoms reduced more easily. By combining these results, the distribution, phase and oxidation state of Zn species on Cu were estimated for the activated state of this model catalyst. This insight into the interplay of Cu and Zn forms the basis for deeper understanding the active sites during methanol synthesis.

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Dedicated to Professor Rüdiger Lange on the occasion of his 65th birthday Small-scale parallel trickle-bed reactors were used to evaluate the performance of a commercial hydrodesulfurization catalyst under industrially relevant conditions. Catalyst extrudates were loaded as a single string in reactor tubes. It is demonstrated that product sulfur levels and densities obtained with the single-pelletstring reactor are close to the results obtained in a bench-scale fixed-bed reactor operated under the same conditions. Moreover, parallel single-pellet-string reactors show high reproducibility. To study the hydrodynamic effects of the catalystbed packing, the catalyst-bed length was varied by loading different amounts of catalysts, and crushed catalyst was also loaded.