An innovative BASF catalyst manufacturing technology (NanoSelect TM ) is introduced which allows production of heterogeneous catalysts with excellent control over metal crystallite sizes. NanoSelect TM technology enabled the development of Pd catalysts which are leadfree Lindlar catalyst replacements in alkyne-to-cis-alkene hydrogenations. NanoSelect TM Pt catalysts showed excellent chemoselectivity in substituted nitro-arene hydrogenation reactions without build-up of hydroxylamine intermediates. All NanoSelect TM produced catalysts show markedly higher activity per gram of metal leading to tenfold less use of precious metal.

In recent years, many articles describing the preparation of supported colloidal catalysts have been published. The semi‐hydrogenation of alkynes to yield cis‐alkenes is often used as a test reaction in these publications. Many highly selective catalysts are described. However, a satisfactory explanation for the high reported selectivity has never been shown. Here we report a study on the possible effects that lead to the large selectivity differences between current commercial Pd/C catalysts and our newly developed NanoSelect catalysts. The focus is on differences in chemical composition as well as catalyst characteristics. We use a focused ion beam scanning electron microscope (FIB‐SEM) to locate the metal particle with respect to the surface of the support. FIB‐SEM analysis clearly shows the absence of the active component inside the support material, which could explain the high observed selectivity. Nevertheless, an effect of the stabilizer cannot be ruled out.

The physicochemical state of a catalyst is a key factor in determining both activity and selectivity; however these materials are often not structurally or compositionally homogeneous. Here we report on the 3-dimensional imaging of an industrial catalyst, Mo-promoted colloidal Pt supported on carbon. The distribution of both the active Pt species and Mo promoter have been mapped over a single particle of catalyst using microfocus X-ray fluorescence computed tomography. X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure revealed a mixed local coordination environment, including the presence of both metallic Pt clusters and Pt chloride species, but also no direct interaction between the catalyst and Mo promoter. We also report on the benefits of scanning μ-XANES computed tomography for chemical imaging, allowing for 2- and 3-dimensional mapping of the local electronic and geometric environment, in this instance for both the Pt catalyst and Mo promoter throughout the catalyst particle.

and showed only minimal non-productive decomposition of the oxidant. Secondary alcohols were selectively oxidized to ketones, while primary alcohols tended to be oxidized to the corresponding carboxylic acids, although secondary alcohols were selectively oxidized in the presence of primary alcohols. Vicinal diols yielded carbon-carbon bond cleavage products in very high yields. Pyridine derivatives were oxidized to the respective N-oxides, but strongly electron-withdrawing moieties inhibited the oxidation reaction. Primary amines were oxidized to the oximes, but significantly hydrolyzed in situ. Aniline derivatives were oxidized to the corresponding azoxy or nitro products depending on the substitution pattern in the aromatic ring. Catalyst recovery and recycle was demonstrated.

Positive discrimination: Supported MoVI promoted Pt nanoparticles (c‐Pt+Mo/C) are successfully applied as catalysts in the chemoselective hydrogenation of functionalized nitroarenes. Mild conditions (30 °C, 4 bar H2, EtOH) prove sufficient for complete reduction to the corresponding anilines, leaving other functional groups untouched. Turnover numbers of at least 20 000 show that this catalyst is very tolerant to halogen‐containing aromatics.