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In this paper, both volatile and strongly adsorbed products of heavy hydrocarbon conversion on a zeolite were investigated by gas‐phase and solid‐state NMR. For this purpose, the reactions were carried out in sealed glass tubes under vacuum to collect the volatile reaction products. This procedure is demonstrated for pure 2‐ethylphenol conversion on ultra‐stabilized zeolite Y leading to both the formation of light alkanes and deoxygenation products. The above‐mentioned method is useful to improve the understanding of heavy hydrocarbon conversion under batch conditions. [ABSTRACT FROM AUTHOR]

Selectively functionalized mesoporous silica may considerably advance heterogeneous catalysis through the controlled immobilization of highly selective complex catalysts inside the mesopores. However, spatially controlled functionalization and the precise analytical verification are still a challenge. In this publication, we report a method, which ensures a selective functionalization of the mesopore surface with a clickable linker and thus makes it possible to study confinement effects during catalyzed reactions. First, we passivate the silanol groups on the particle surface and in the pore entrances of the mesoporous silica material SBA‐15 with 1,1,1‐trimethyl‐N‐(trimethylsilyl)silanamine. Then we remove the template by solvent extraction and functionalize the pore walls with 3‐azidopropyltriethoxysilane before we click the catalyst. In initial experiments of asymmetric Rh‐catalyzed 1,2‐addition, we investigate the performance of a catalyst clicked selectively in the mesopores and compare it to the dissolved catalyst as well as to the catalyst immobilized exclusively on the external surface of SBA‐15. [ABSTRACT FROM AUTHOR]

Experimental evidence for the presence of tert-butyl cations, which are important intermediates in acid-catalyzed heterogeneous reactions, on solid acids has still not been provided to date. By combining density functional theory (DFT) calculations with 1H/13C magic-angle-spinning NMR spectroscopy, the tert-butyl cation was successfully identified on zeolite H-ZSM-5 upon conversion of isobutene by capturing this intermediate with ammonia. [ABSTRACT FROM AUTHOR]

Triphenylphosphine (PPh 3) is demonstrated to be a useful molecular probe and tool for quantitatively characterizing the spatial distribution of noble metals on porous supports. The preparation of metal organic complexes by loading the supports with PPh 3 was performed by physically mixing the water-free catalysts with solid PPh 3 powder in nitrogen atmosphere and heating this mixture at 363 K for 20 h. Based on quantitative 31P MAS NMR spectroscopy, the formation of noble metal (NM) tetrakis(triphenylphosphine) complexes (PPh 3) 4 NM on Pt- and Rh-containing silica and SBA-15 supports was evidenced. The large specific surface areas and mesopore diameters (3.4–4.5 nm) of these supports provide suitable conditions for the quantitative formation of (PPh 3) 4 NM complexes with a molecule size of ca. 2 nm. The micropores and cages of zeolites Y (0.72 and 1.14 nm, respectively), on the other hand, are too small for the formation of these complexes. Consequently, quantitative 31P MAS NMR investigations of noble metal containing zeolites Y indicated that only 7% of the Pt and 6% of the Rh atoms are accessible for the complex formation with PPh 3. In other words, these noble metal quantities are located outside of the micropores and cages of the zeolite particles. The non-involved 93% of Pt and 94% of Rh atoms on the zeolites Y under study are located inside the micropores and cages of this support material, making them available for shape-selective heterogeneous catalysis. Image 1 • Dispersed Pt and Rh reacts with PPh 3 to tetrakis(triphenylphosphine) complexes. • Complexation of metal atoms with PPh 3 in mesopores or on the surface. • Quantitative determination of accessible Pt and Rh by 31P MAS NMR. • No complexation of metal atoms with PPh 3 inside micropores. • Method for determining noble metal location in pores or on particle surface. [ABSTRACT FROM AUTHOR]