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The development of cheap and robust heterogeneous catalysts for the Meerwein‐Ponndorf‐Verley (MPV) reduction is desirable due to the difficulties in product isolation and catalyst recovery associated with the traditional use of homogeneous catalysts for MPV. Herein, we show that microwave heated γ‐Al2O3 can be used for the reduction of aldehydes to alcohols. The reaction is efficient and has a broad substrates scope (19 entries). The products can be isolated by simple filtration, and the catalyst can be regenerated. With the use of microwave heating, we can direct the heating to the catalyst rather than to the whole reaction medium. Furthermore, DFT was used to study the reaction mechanism, and we can conclude that a dual‐site mechanism is operative where the aldehyde and 2‐propoxide are situated on two adjacent Al sites during the reduction. Additionally, volcano plots were used to rationalize the reactivity of Al2O3 in comparison to other metal oxides. [ABSTRACT FROM AUTHOR]

Fuel cells have the potential to play an important role in sustainable energy systems, provided that catalysts with higher activity and stability are developed. In this work, it is found that thin alloy films of single-target cosputtered platinum-yttrium exhibit up to seven times higher specific activity (13.4 ± 0.4 mA cm−2) for the oxygen reduction reaction (ORR) than polycrystalline platinum, and up to one order of magnitude higher mass activity (3.5 ± 0.3 A mg−1) than platinum nanoparticles. These alloys have the highest reported ORR activity for an as-deposited material, i.e., without any additional chemical or thermal treatment. The films show an improvement in stability over the same materials in nanoparticulate form. Physical characterization shows that the thin films form a platinum overlayer supported on an underlying alloy. The high activity is likely related to compressive strain in that overlayer. As sputtering can be used to mass-produce fuel cell electrodes, the results open new possibilities for the preparation of platinum-rare earth metal alloy catalysts in commercial devices. [ABSTRACT FROM AUTHOR]

In catalysis, nanoparticles enable chemical transformations and their structural and chemical fingerprints control activity. To develop understanding of such fingerprints, methods studying catalysts at realistic conditions have proven instrumental. Normally, these methods either probe the catalyst bed with low spatial resolution, thereby averaging out single particle characteristics, or probe an extremely small fraction only, thereby effectively ignoring most of the catalyst. Here, we bridge the gap between these two extremes by introducing highly multiplexed single particle plasmonic nanoimaging of model catalyst beds comprising 1000 nanoparticles, which are integrated in a nanoreactor platform that enables online mass spectroscopy activity measurements. Using the example of CO oxidation over Cu, we reveal how highly local spatial variations in catalyst state dynamics are responsible for contradicting information about catalyst active phase found in the literature, and identify that both surface and bulk oxidation state of a Cu nanoparticle catalyst dynamically mediate its activity. Characterizing individual catalyst nanoparticles at operando conditions is a cornerstone of catalysis research. Here the authors utilize plasmonic optical nanoimaging in a nanofluidic reactor to map the impact of reactor geometry on single Cu particle oxidation state dynamics and active phase during CO oxidation. [ABSTRACT FROM AUTHOR]

The high activity for the oxygen reduction reaction of thin platinum‐yttrium films is highlighted by Niklas Lindahl and co‐workers in article number 1700311. The alloy thin films are formed by sputtering using plasma (purple) from a target of platinum (gray) with attached foils of yttrium (blue). In acid, a strained platinum overlayer is formed. The strained surface provides improved activity for the reduction of oxygen (red), which is rate limiting when converting protons (white) into water while producing electrical energy in fuel cells. [ABSTRACT FROM AUTHOR]