Energetic and Kinetic Competition on the Stability of Pd13 Clusters: Ab Initio Molecular Dynamics Simulations

Material stability is the focus on both experiments and calculations, which includes the energetic stability at the static state and the thermodynamic stability at the kinetic state. To show whether energetics or kinetics dominates on material stability, this study focuses on the Pd13 clusters, because of their observable magnetic moment in experiment. Energetically, the CALYPSO searching method and first-principles calculations find that Pd13(C2) is the ground state at 0 K while the static frequency calculations demonstrate that the icosahedron Pd13(Ih) becomes more favorable on free energy as temperature increases. However, their magnetic moments (8 μB) are not in agreement with the experimental value (<5.2 μB). Kinetically, ab initio molecular dynamics simulations reveal that Pd13(C3v) (6 μB) has supreme isomerization temperature and the other 11 low-lying isomers transform to Pd13(C3v) directly or indirectly, demonstrating that Pd13(C3v) has the maximum probability to be observed in experiment. The magnetic moment difference between experiment (<5.2 μB) and this calculation (6 μB) may be due to the spin multiplicities. Our result suggests that the magnetic moment disparity between theory and experiment (in Pd13 clusters) originates from the kinetic stability.

Shielded goethite catalyst that enables fast water dissociation in bipolar membranes

Optimal pH conditions for efficient artificial photosynthesis, hydrogen/oxygen evolution reactions, and photoreduction of carbon dioxide are now successfully achievable with catalytic bipolar membranes-integrated water dissociation and in-situ acid-base generations. However, inefficiency and instability are severe issues in state-of-the-art membranes, which need to urgently resolve with systematic membrane designs and innovative, inexpensive junctional catalysts. Here we show a shielding and in-situ formation strategy of fully-interconnected earth-abundant goethite Fe⁺³O(OH) catalyst, which lowers the activation energy barrier from 5.15 to 1.06 eV per HO − H bond and fabricates energy-efficient, cost-effective, and durable shielded catalytic bipolar membranes. Small water dissociation voltages at limiting current density (U_LCD: 0.8 V) and 100 mA cm⁻² (U₁₀₀: 1.1 V), outstanding cyclic stability at 637 mA cm⁻², long-time electro-stability, and fast acid-base generations (H₂SO₄: 3.9 ± 0.19 and NaOH: 4.4 ± 0.21 M m⁻² min⁻¹ at 100 mA cm⁻²) infer confident potential use of the novel bipolar membranes in emerging sustainable technologies.

Bipolar membranes integrated water dissociation and acid-base generations have great potential in emerging sustainable technologies but remains inefficient. Here, the authors circumvent this inefficiency and instability of the membranes by developing polyaniline shielded catalytic bipolar membranes.

σ-Holes and σ-lumps direct the Lewis basic and acidic interactions of noble metal nanoparticles: introducing regium bonds

Using local DFT-based probes for electrostatic as well as charge transfer/polarization interactions, we are able to characterize Lewis basic and acidic sites on copper, silver and gold nanoparticles.

Molecular and dissociative adsorption of water and hydrogen sulfide at perfect and defective Cu(110) surfaces

The adsorption of H₂O and H₂S onto Cu(110) surfaces lead to considerably different geometries and surface reconstruction and relaxation mechanisms.

Reactivity at the Cu2O(100):Cu–H2O interface: a combined DFT and PES study

Detailed characterization of the structure and composition of the water–cuprite interface.