The dissolution of Fe and Ni from Pt 1Ϫx M x ͑M ϭ Fe, Ni; 0 Ͻ x Ͻ 1͒ oxygen reduction electrocatalysts was studied under simulated operating conditions ͑low pH, 80°C͒ of proton exchange membrane ͑PEM͒ fuel cells. The alloys were prepared combinatorially by sputtering Pt and M ͑M ϭ Fe, Ni͒ onto thin films of nanostructured whisker-like supports, and mapped over the entire composition range of the binary systems. For 0 Ͻ x Ͻ 1.0, we observe the formation of randomly ordered substitutional solid solutions of Pt 1Ϫx Fe x and Pt 1Ϫx Ni x alloys. Electron microprobe measurements show that transition metals are removed from all compositions during acid treatment, but that the percentage removed increases with x, acid strength, and temperature. For small values of x (x Ͻ 0.6) no substantial changes in the lattice size are observed upon dissolution of Fe or Ni suggesting that the dissolved transition metals originate from the surface. However, for electrocatalysts with x Ͼ 0.6, the lattice constant expands indicating that transition metals dissolve also from the bulk. X-ray photoelectron spectroscopy results show complete removal of surface Ni ͑Fe͒ after acid treatment at 80°C for all compositions. The results of the acid treatments compare well to the composition changes that occur when a Pt 1Ϫx Fe x or Pt 1Ϫx Ni x combinatorial catalyst library is used in an operating PEM fuel cell.

Non‐innocent ligands (NILs) like bis(pyridylimino)isoindolide (BPI) play crucial roles in coordination chemistry, biosciences, catalysis and material sciences. Investigating the isolated redox states of NILs is inevitable for understanding their redox‐activity and fine‐tuning the properties of corresponding metal complexes. The limited number of fundamental studies on the coordination behavior and redox chemistry of reduced BPI species is suggested to hamper further applications of the title compounds. This work describes for the first time the isolation of alkali metal complexes of BPI and Me2BPI in three different oxidation states and their characterization by means of NMR or EPR spectroscopy, DFT calculations, and SC‐XRD studies. The latter revealed the connection between bond orders in the ligand scaffold and its oxidation state. The paramagnetic compound Me2BPI‐K2 was isolated as a coordination copolymer with 18‐crown‐6, which enabled the characterization of the dianionic BPI radical. Furthermore, the so‐far unknown trianionic state of BPI was reported by the isolation of BPI‐K3. This divulges an unprecedented bis(amidinato)isoindolide coordination mode.

Grapes are widely known for health benefits due to their antioxidant content. In wine production, grape stems are often discarded, though they has a higher content of antioxidants than the juice. The effectiveness of using an environmentally friendly solvent, ethanol, as a superheated liquid and supercritical fluid to extract antioxidant compounds from grape stems of organically grown Crimson Seedless grapes was evaluated. The Ferric Reducing Ability of Plasma (FRAP) assay and the Total Phenolic Content (TPC), or Folin‐Ciocalteu assay, were used to quantify the antioxidant power of grape stem extracts. The extractions were performed at temperatures between 160°C and 300°C at constant density. It was found that the optimal extraction temperature was 204°C, at superheated liquid conditions, with a FRAP value of 0.670 mmol Trolox Equivalent/g of dry grape stem. The FRAP values were higher than other studies that extracted antioxidants from grape stems using single‐pass batch extraction.

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