Spin evolution and flip in the oxygen reduction reaction: a theoretical study of Cu(Ni)XP₂S₆(X = In, Bi and Cr)

Abstract

The local spin state has attracted increasing attention for its critical role to improve the catalytic performance in catalysis. However, the mechanism behind it has not been clearly understood so...

Effect of ferroelectric polarization on the oxygen evolution reaction: a theoretical study of MIrSn2S6 (M = Bi, Mn, and Sb)

“…To obtain the adsorption energies (E ad ) of the proton, water molecule, and intermediates in the OER process (*OH, *O, *OOH, and *OO), the spin state is carefully checked. 50 We nd that only *OO shows clear spin polarization (Fig. S13 and S19 †).…”

“…The net magnetic moment of *OO is generally 2 m B , such as in PE-MnIrSn 2 S 6 , which is consistent with our previous study. 50 However, the net magnetic moment of *OO is ∼1.5 m B in one excited state in FE-MnIrSn 2 S 6 (Fig. S13 †), which is different from those in PE-MnIrSn 2 S 6 and the other two substrates.…”

Multiferroicity in 2D MSX2 (M = Nb and Zr; X = Cl, Br, and I)

“…2 ), (16) where e ij is piezoelectric stress coefficients and C ij is stiffness tensors. Due to smaller C 22 and larger off-center displacement of metal atoms, the strain coefficients become significant under tension along the direction of FE switching (Table 3).…”

“…14,15 Commonly, there is an off-center displacement in FE phases other than the PE phase, indicating the break of symmetry for FE polarization. 10,[16][17][18] Taking 2D VOCl 2 as an example, the off-center displacement of V ions contributes to FE characteristics, and the energy barrier of the FE flip is 0.18 eV, which stabilizes the ferroelectricity. 19 2D TiOBr 2 exhibits significant piezoelectricity with d 11 = 37.758 pm V À1 , resulting from low in-plane elastic constants and atomic sensitivity to an applied strain.…”

Transition metal embedded in two‐dimensional bi‐BN as high activity single atom electrocatalyst for oxygen reduction reactions

“…Due to the growing energy crisis and environmental concerns, there is a greater emphasis on research into green energy technologies, for instance, fuel cells, water separation cells and metal‐air batteries. Proton exchange membrane fuel cells (PEMFCs) [1–3] are regarded as one of the most promising substitutes for conventional energy resources due to their high efficiency and low emission characteristics. Nevertheless, sluggish kinetics of the cathodic oxygen reduction reaction (ORR) constrains the performance of these fuel cells.…”