13775-30-9Relevant articles and documents
Boosting the acidic electrocatalytic nitrogen reduction performance of MoS2 by strain engineering
Cai, Weiwei,Li, Jing,Liang, Jiawei,Liu, Zhao,Ma, Shuangxiu,Qu, Konggang,Wang, Yangang,Wu, Junli,Yang, Zehui,Zhang, Quan
, p. 10426 - 10432 (2020)
It has been widely confirmed that expanding the layer spacing of layer-structured MoS2 can boost the hydrogen evolution reaction (HER) activity of MoS2. Inspired by this, a strain engineering strategy was applied to defect-rich MoS2 nanosheets by facilely substituting F to compress the interlayer space of MoS2. Because of the smaller size and higher electronegativity of F as compared to S, the catalytic HER was remarkably suppressed. By considering the strongly reduced uphill energy for the hydrogenation of adsorbed N2 on MoS2 due to the introduction of F ions, as revealed by first-principles calculations, electrochemical nitrogen reduction reaction (NRR) activity and selectivity on the F-doped MoS2 (F-MoS2) catalyst under acidic conditions can be significantly boosted. Faradaic efficiency toward the NRR on F-MoS2 was therefore enhanced to 20.6% with a maximum NH3 yield of 35.7 μg h-1 mgcat-1 at -0.2 V vs. RHE during long-term operation.
Heptanuclear antiferromagnetic Fe(III)-d-(-)-quinato assemblies with an S = 3/2 ground state - PH-specific synthetic chemistry, spectroscopic, structural, and magnetic susceptibility studies
Menelaou,Vournari,Psycharis,Raptopoulou,Terzis,Tangoulis,Sanakis,Mateescu,Salifoglou
, p. 13849 - 13860 (2013)
Iron is an essential metal ion with numerous roles in biological systems and advanced abiotic materials. d-(-)-Quinic acid is a cellular metal ion chelator, capable of promoting reactions with metal M(II,III) ions under pH-specific conditions. In an effort to comprehend the chemical reactivity of well-defined forms of Fe(III)/Fe(II) toward α-hydroxycarboxylic acids, pH-specific reactions of: (a) [Fe3O(CH3COO) 6(H2O)3]·(NO3)·4H 2O with d-(-)-quinic acid in a molar ratio 1:3 at pH 2.5 and (b) Mohr's salt with d-(-)-quinic acid in a molar ratio 1:3 at pH 7.5, respectively, led to the isolation of the first two heptanuclear Fe(III)-quinato complexes, [Fe7O3(OH)3(C7H10O 6)6]·20.5H2O (1) and (NH 4)[Fe7(OH)6(C7H10O 6)6]·(SO4)2·18H 2O (2). Compounds 1 and 2 were characterized by analytical, spectroscopic (UV-vis, FT-IR, EPR, and Moessbauer) techniques, CV, TGA-DTG, and magnetic susceptibility measurements. The X-ray structures of 1 and 2 reveal heptanuclear assemblies of six Fe(III) ions bound by six doubly deprotonated quinates and one Fe(III) ion bound by oxido- and hydroxido-bridges (1), and hydroxido-bridges (2), all in an octahedral fashion. Moessbauer spectroscopy on 1 and 2 suggests the presence of Fe(III) ions in an all-oxygen environment. EPR measurements indicate that 1 and 2 retain their structure in solution, while magnetic measurements reveal an overall antiferromagnetic behavior with a ground state S = 3/2. The collective physicochemical properties of 1 and 2 suggest that the (a) nature of the ligand, (b) precursor form of iron, (c) pH, and (d) molecular stoichiometry are key factors influencing the chemical reactivity of the binary Fe(II,III)-hydroxycarboxylato systems, their aqueous speciation, and ultimately through variably emerging hydrogen bonding interactions, the assembly of multinuclear Fe(III)-hydroxycarboxylato clusters with distinct lattice architectures of specific dimensionality (2D-3D) and magnetic signature.