A new strategy affords “non‐nano” carbon materials as dehydrogenation catalysts that perform similarly to nanocarbons. Polymer‐based carbon precursors that combine a soft‐template approach with ion adsorption and catalytic graphitization are key to this synthesis strategy, thus offering control over macroscopic shape, texture, and crystallinity and resulting in a hybrid amorphous/graphitic carbon after pyrolysis. From this intermediate the active carbon catalyst is prepared by removing the amorphous parts of the hybrid carbon materials via selective oxidation. The oxidative dehydrogenation of ethanol was chosen as test reaction, which shows that fine‐tuning the synthesis of the new carbon catalysts allows to obtain a catalytic material with an attractive high selectivity (82 %) similar to a carbon nanotube reference, while achieving 10 times higher space–time yields at 330 °C. This new class of carbon materials is accessible via a technically scalable, reproducible synthetic pathway and exhibits spherical particles with diameters around 100 μm, allowing unproblematic handling similar to classic non‐nano catalysts.

Iron molybdate catalysts are applied in the industrial FormOx process to produce formaldehyde by oxidative dehydrogenation (ODH) of methanol. Only few studies are available about the applicability of iron molybdate catalysts for the ODH of ethanol to produce acetaldehyde. Herein, an iron molybdate synthesized by co-precipitation (p) and an iron molybdate prepared by a ball-milling solid-state synthesis (bm) are applied as ethanol ODH catalysts. Both materials show attractive acetaldehyde selectivites of > 90 % (280 °C: p-Fe 2 (MoO 4 ) 3 : Y AcH = 90.3 %; bm-Fe 2 (MoO 4 ) 3 : Y AcH = 60.4 %) and a stable performance.The bulk composition and crystal structure could be confirmed by various characterization techniques and is maintained during ethanol ODH. XPS reveals an enrichment of Mo on the catalyst surface which is slightly decreasing after the catalytic tests. This observation could be a first sign of long-term deactivation like known from methanol ODH. Comparing the performance of both materials, p-Fe 2 (MoO 4 ) 3 shows higher activity and aldehyde selectivity. We propose the higher Mo/Fe surface ratio and the lower acidity to be the reasons for these differences.

Until now, oxygen functionalized carbon materials were not considered to exhibit significant acidity at high temperatures, since carboxylic acids, the most prominent acidic functionality, are prone to decarboxylation at temperatures exceeding 250 °C. Paradoxically, we could show that oxidized carbon materials can act as highly active high-temperature solid acid catalysts in the dehydration of methanol at 300 °C, showing an attractive selectivity to dimethyl ether (DME) of up to 92 % at a conversion of 47 %. Building on a tailor-made carbon model material, we developed a strategy to utilize in situ DRIFT spectroscopy for the analysis of carbon surface species under process conditions, which until now proofed to be highly challenging due to the high intrinsic absorbance of carbon. By correlating the catalytic behavior with a comprehensive in situ DRIFTS study and extensive post mortem analysis we could attribute the hightemperature acidity of oxidized carbons to the interaction of thermally stable carboxylic anhydrides and lactones with nucleophilic constituents of the reaction atmosphere e. g. methanol and H 2 O. Dynamic equilibria of surface oxides depending on reaction atmosphere and temperature were observed, and a methyl ester, formed by methanolysis of anhydrides and lactones, was identified as key intermediate for DME generation on oxidized carbon catalysts.

Selective oxidation reactions are an important class of the current chemical industry and will be highly important for future sustainable chemical production. Especially, the selective oxidation of primary alcohols is expected to be of high future interest, as alcohols can be obtained on technical scales from biomass fermentation. The oxidation of primary alcohols produces aldehydes, which are important intermediates. While selective methanol oxidation is industrially established, the commercial catalyst suffers from deactivation. Ethanol selective oxidation is not commercialized but would give access to sustainable acetaldehyde production when using renewable ethanol. In this work, it is shown that employing 2D MXenes as building blocks allows one to design a nanostructured oxide catalyst composed of mixed valence vanadium oxides, which outperforms on both reactions known materials by nearly an order of magnitude in activity, while showing high selectivity and stability. The study shows that the synthesis route employing 2D materials is key to obtain these attractive catalysts. V 4 C 3 T x MXene structured as an aerogel precursor needs to be employed and mildly oxidized in an alcohol and oxygen atmosphere to result in the aspired nanostructured catalyst composed of mixed valence VO 2 , V 6 O 13 , and V 3 O 7 . Very likely, the bulk stable reduced valence state of the material together coupled with the nanorod arrangement allows for unprecedented oxygen mobility as well as active sites and results in an ultra-active catalyst.

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