Chromium doped Li₂RuO₃ as a positive electrode with superior electrochemical performance for lithium ion batteries

Abstract

Cr-Doped LiRuO of the LiRuCrO (x = 0, 0.02, 0.05, 0.1) series was successfully synthesized and the effect of Cr on the electrochemical performance of LiRuO was systematically investigated. The results show that LiRuCrO exhibits the best performance in terms of capacity, rate capability and cycling stability.

A Computational Comparison of Oxygen Atom Transfer Catalyzed by Dimethyl Sulf­oxide Reductase with Mo and W

“…The transition structure corresponded to the (Me) 2 S=O double-bond cleavage and is similar to the crystal structures of the enzyme in both the oxidized and reduced states. [13] Later studies by Thapper, [14] McNamara, [15,16] Hernandez-Marin and Ziegler, [17] Solomon, [18,19] Hofmann, [20,21] and us [22][23][24] have established a two-step associative mechanism, in which DMSO first binds to the reduced active site, and the S-O bond is cleaved in the second step concomitant with the oxidization of the Mo ion to the Mo VI state (see Scheme 1). The second step is rate limiting and has a predicted activation energy of 76, [14] 80, [15] 69, [17] 68, [18,19] 40, [20,21] or 63 kJ/mol.…”

“…[11,[13][14][15][16][17][18][19][20][21][22]24,26] We use thirteen different DFT methods to optimize structures along the reaction pathway, both in the gas phase and with a continuum solvent. Accurate energies are obtained by single-point calculations at the coupledcluster level of theory.…”

Xanthine Dehydrogenase Active Site: Chiral Switching and Substrate Coordination

“…As pointed early on, the transfer of hydride from substrate to the Mo(VI)=S fragment of the enzyme cofactor is the principal reaction coordinate and constitutes the formal transfer of two reducing equivalents from substrate to the enzyme. Calculations with oxo-congeners of the enzyme molybdopterin center, [46,39,41] on the one hand, and the formamide thioxo-congener substrate, on the other hand [Ilich & Hille, unpublished calculations], show that absent any of the changes associated with the substrate carbon atom re-hybridization the oxidoreductive reaction will not take place in either case. It should also be noted that in formamide -a small, simple and relatively flexible molecule [59] -the electronic structure changes leading to formation of transition state are centered on the target carbon atom.…”

“…[51,52] Step #6: The preceding Mo-pterin coordination is that of the oxidized, reaction-ready Mo(VI) center in the active site of xanthine and aldehyde oxidoreductive enzymes, XDH, AOXA, XO, XOR. Following the metathetic exchange with substrate, Scheme 3, the Mo(VI)-center loses the O(H) ligand to the substrate to become a twoelectron-reduced Mo(IV) tetrahedral complex, [31,41] (a), or, as invoked in early mechanistic considerations and suggested by some x-ray structural studies [43] a 5-coordinated aquaMo(IV) complex (b):…”

“…One direction followed an extension of the size of the Mo-enedithiolate : formamide model, from the initial 17-atom reaction pair, [28][29][30][31] to a 39 atom model with the inclusion of xanthine substrate, [38] and to a 23357-atom cluster comprising, in addition to the enzyme-substrate reacting pair, solvent molecules treated by molecular mechanics, MM, methods. [39] The other direction was focused principally on the use of more refined and also more varied theoretical formalism, for example the CCSD(T) formalism [40,41] and a number of DFT methods. While expanding the theater of possible atomic XDH: FADH + NADP + → FAD + NADPH XO: FADH + O2 → O2 -+ H2O2 Scheme 2.…”