Tin goes in: The solid Lewis acid Sn‐zeolite β is obtained in a simple and scalable procedure (see scheme). A high metal content can be obtained, without undesirable side‐effects. The space‐time‐yields of the resulting catalysis are over one order‐of‐magnitude larger than those of the state‐of‐the‐art materials for the Baeyer–Villiger oxidation of cyclohexanone and the synthesis of ethyl lactate from the triose dihydroxyacetone.

The economically viable oxidative upgrading of methane presents one of the most difficult but rewarding challenges within catalysis research. Its potential to revolutionalise the chemical value chain, coupled with the associated supremely challenging scientific aspects, has ensured this topic's high popularity over the preceeding decades. Herein, we report a non-exhaustive account of the current developments within the field of oxidative methane upgrading and summarise the pertaining challenges that have yet to be solved.

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A two-step procedure for the post-synthetic preparation of Lewis acidic Sn-, Zr- and Ti-zeolite β is reported. Dealumination of a commercially available Al-β zeolite leads to the formation of highly siliceous material containing silanol nests, which can be filled in a second step via the solid-state ion-exchange or impregnation of an appropriate metal precursor. Spectroscopic studies indicate that each metal is subsequently coordinated within the zeolite framework, and that little or no bulk oxides are formed--despite the high metal loadings. The synthesised catalysts demonstrate excellent activity for the isomerisation of glyceraldehyde to dihydroxyacetone, a key model reaction for the upgrading of bio-renewable feedstocks, and the epoxidation of bulky olefins.

We investigate the chemical reactions involved during the synthesis of supported vanadium oxide catalysts using chemical grafting of vanadium oxytriisopropoxide (VO(O i Pr) 3 ) to thermally pretreated silica under solvent-free conditions. VO(O i Pr) 3 is found to react with both site-isolated silanol (Si−OH) groups and strained siloxane ( Si−O−Si) bridges at the silica surface. Solid-state 51 V and 13 C MAS NMR confirms the formation of two slightly different vanadium species associated with the two anchoring mechanisms. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), in situ Raman spectroscopy, and thermogravimetric analysis-differential scanning calorimetry-mass spectrometry (TGA-DSC-MS) were used to study the subsequent calcination, revealing the formation of a transient VOH intermediate upon the release of propene, followed by the formation of isolated VO 4 surface species upon elimination of water. X-ray absorption spectroscopy (XAS) and 51 V MAS NMR of the calcined material confirm the conversion of the two original vanadium sites to a species with a single isotropic shift, confirming the formation of isolated, tetrahedral VO 4 sites.

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Amorphous zeolitic imidazolate frameworks (ZIFs) offer promising applications as novel functional materials. Herein, amorphization of ZIF-L through scanning-electron-beam exposure is demonstrated, based on amorphization of individual ZIF-L crystals. The amorphized ZIF product has drastically increased stability against dissolution in water. An electron dose that allows for complete preservation of amorphous particles after immersion in water is established, resulting in new shapes of amorphous ZIF-L with spatial control at the sub-micrometer length scale. Changed water stability as a consequence of scanning-electron-beam exposure is demonstrated for three additional metal-organic frameworks (ZIF-8, Zn(BeIm)OAc, MIL-101), highlighting the potential use of an electron beam for top-down MOF patterning. Lastly, recrystallization of ZIF-L in the presence of linker is studied and shows distinct differences for crystalline and amorphized material.