Latest Publications

The Journal of Physical Chemistry C 2018

DOI: 10.1021/acs.jpcc.8b02174

A comprehensive density functional theory investigation of conduction mechanisms of both intrinsic and extrinsic species found in oxide–carbonate composite electrolyte materials used in solid oxide fuel cell is presented. An interface model of yttria-stabilized zirconia–LiKCO3 is used as a case study to investigate transport properties, considering different mechanistic assumptions suggested in the literature over the years. Results clearly indicate that interfaces play an extremely important role in influencing the ionic conductivity performances of these electrolytes. In particular, redistribution of ions of both phases can lead to the formation of the so-called space-charge layer at the interface, which then favorably influences the transport of intrinsic cations or extrinsic protons in particular. These results constitute an important first step toward the understanding of the electrochemical processes and transpo...

ACS Catalysis 2018

DOI: 10.1021/acscatal.8b00933

The mechanism of boron-to-nickel transmetalation, the key step of the nickel-catalyzed Suzuki-Miyaura (S-M) coupling, was examined both experimentally and theoretically. Dinuclear μ-hydroxo-bridged complexes formed by reaction of trans-[ArNi(PR3)2X] with hydroxide are not directly involved in transmetalation, but they rather act as a resting state for the catalyst. The base/boronic acid ratio is the crucial parameter, as it modulates the extent of formation of these dinuclear species and thus tunes the catalytic activity. These findings explain some limitations encountered in practical applications of nickel-catalyzed S-M couplings and suggest how to tailor the experimental conditions in order to overcome these difficulties.

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