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1. Enhancement of Ni–(Y ₂ O ₃ ) _0.08 (ZrO ₂ ) _0.92 fuel electrode performance by infiltration of Ce _0.8 Gd _0.2 O _2−δ nanoparticles

   https://doi.org/10.1039/c9ta12316d  

   Park, Beom-Kyeong; Scipioni, Roberto; Cox, Dalton; Barnett, Scott A. (February 2020, Journal of Materials Chemistry A)

   This paper addresses the use of Ce 0.8 Gd 0.2 O 2−δ (GDC) infiltration into the Ni–(Y 2 O 3 ) 0.08 (ZrO 2 ) 0.92 (YSZ) fuel electrode of solid oxide cells (SOCs) for improving their electrochemical performance in fuel cell and electrolysis operation. Although doped ceria infiltration into Ni–YSZ has recently been shown to improve the electrode performance and stability, the mechanisms defining how GDC impacts electrochemical characteristics are not fully delineated. Furthermore, the electrochemical characteristics have not yet been determined over the full range of conditions normally encountered in fuel cell and electrolysis operation. Here we present a study of both symmetric and full cells aimed at understanding the electrochemical mechanisms of GDC-modified Ni–YSZ over a wide range of fuel compositions and temperatures. Single-step GDC infiltration at an appropriate loading substantially reduced the polarization resistance of Ni–YSZ electrodes in electrolyte-supported cells, as measured using electrochemical impedance spectroscopy (EIS) at various temperatures (600–800 °C) in a range of H 2 O–H 2 mixtures (3–90 vol% H 2 O). Fuel-electrode-supported cells had significant concentration polarization due to the thick Ni–YSZ supports. A distribution of relaxation times approach is used to develop a physically-based electrochemical model; the results show that GDC reduces the reaction resistance associated with three-phase boundaries, but also appears to improve oxygen transport in the electrode. Increasing the H 2 O fraction in the H 2 –H 2 O fuel mixture reduced both the three-phase boundary resistance and the gas diffusion resistance for Ni–YSZ; with GDC infiltration, the electrode resistance showed less variation with fuel composition. GDC infiltration improved the performance of fuel-electrode-supported full cells, which yielded a maximum power density of 2.28 W cm −2 in fuel cell mode and an electrolysis current density at 1.3 V of 2.22 A cm −2 , both at 800 °C. 

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2. On comparison of luminescence properties of La ₂ Zr ₂ O ₇ and La ₂ Hf ₂ O ₇ nanoparticles

   https://doi.org/10.1111/jace.16693  

   Gupta, Santosh K.; Abdou, Maya; Ghosh, Partha S.; Zuniga, Jose P.; Manoharan, Ezhilarasan; Kim, HyeongJun; Mao, Yuanbing (August 2019, Journal of the American Ceramic Society)
3. Synthesis, structures, and reactivity of isomers of [RuCp*(1,4-(Me ₂ N) ₂ C ₆ H ₄ )] ₂

   https://doi.org/10.1039/D1DT02155A  

   Longhi, Elena; Risko, Chad; Bacsa, John; Khrustalev, Victor; Rigin, Sergei; Moudgil, Karttikay; Timofeeva, Tatiana V.; Marder, Seth R.; Barlow, Stephen (September 2021, Dalton Transactions)

   [RuCp*(1,3,5-R 3 C 6 H 3 )] 2 {Cp* = η 5 -pentamethylcyclopentadienyl, R = Me, Et} have previously been found to be moderately air stable, yet highly reducing, with estimated D + /0.5D 2 (where D 2 and D + represent the dimer and the corresponding monomeric cation, respectively) redox potentials of ca. −2.0 V vs. FeCp 2 +/0 . These properties have led to their use as n-dopants for organic semiconductors. Use of arenes substituted with π-electron donors is anticipated to lead to even more strongly reducing dimers. [RuCp*(1-(Me 2 N)-3,5-Me 2 C 6 H 3 )] + PF 6 − and [RuCp*(1,4-(Me 2 N) 2 C 6 H 4 )] + PF 6 − have been synthesized and electrochemically and crystallographically characterized; both exhibit D + /D potentials slightly more cathodic than [RuCp*(1,3,5-R 3 C 6 H 3 )] + . Reduction of [RuCp*(1,4-(Me 2 N) 2 C 6 H 4 )] + PF 6 − using silica-supported sodium–potassium alloy leads to a mixture of isomers of [RuCp*(1,4-(Me 2 N) 2 C 6 H 4 )] 2 , two of which have been crystallographically characterized. One of these isomers has a similar molecular structure to [RuCp*(1,3,5-Et 3 C 6 H 3 )] 2 ; the central C–C bond is exo , exo , i.e. , on the opposite face of both six-membered rings from the metals. A D + /0.5D 2 potential of −2.4 V is estimated for this exo , exo dimer, more reducing than that of [RuCp*(1,3,5-R 3 C 6 H 3 )] 2 (−2.0 V). This isomer reacts much more rapidly with both air and electron acceptors than [RuCp*(1,3,5-R 3 C 6 H 3 )] 2 due to a much more cathodic D 2 ˙ + /D 2 potential. The other isomer to be crystallographically characterized, along with a third isomer, are both dimerized in an exo , endo fashion, representing the first examples of such dimers. Density functional theory calculations and reactivity studies indicate that the central bonds of these two isomers are weaker than those of the exo , exo isomer, or of [RuCp*(1,3,5-R 3 C 6 H 3 )] 2 , leading to estimated D + /0.5D 2 potentials of −2.5 and −2.6 V vs. FeCp 2 +/0 . At the same time the D 2 ˙ + /D 2 potentials for the exo , endo dimers are anodically shifted relative to those of [RuCp*(1,3,5-R 3 C 6 H 3 )] 2 , resulting in much greater air stability than for the exo , exo isomer. 

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4. Effect of Deuteration on Morphology of 2D Perovskite (CH ₃ NH ₃ ) ₂ Pb(SCN) ₂ I ₂

   https://doi.org/10.1017/S1431927622010558  

   Ware, Washat Roxanne; Ede, Sivasankara Rao; Wells, Rachel; Luo, Zhiping; Gautam, Bhoj (August 2022, Microscopy and Microanalysis)
5. Conversion of Single Crystal (NH ₄ ) ₂ Mo ₃ S ₁₃ ·H ₂ O to Isomorphic Pseudocrystals of MoS ₂ Nanoparticles

   https://doi.org/10.1021/acs.chemmater.8b01247  

   Islam, Saiful M.; Cain, Jeffrey D.; Shi, Fengyuan; He, Yihui; Peng, Lintao; Banerjee, Abhishek; Subrahmanyam, Kota S.; Li, Yuan; Ma, Shulan; Dravid, Vinayak P.; et al (May 2018, Chemistry of Materials)