Solvated electrons in liquid water are one of the seemingly simplest, but most important, transients in chemistry and biology, but they have resisted disclosing important information about their energetics, binding motifs and dynamics. Here we report the first ultrafast liquid-jet photoelectron spectroscopy measurements of solvated electrons in liquid water. The results prove unequivocally the existence of solvated electrons bound at the water surface and of solvated electrons in the bulk solution, with vertical binding energies of 1.6 eV and 3.3 eV, respectively, and with lifetimes longer than 100 ps. The unexpectedly long lifetime of solvated electrons bound at the water surface is attributed to a free-energy barrier that separates surface and interior states. Beyond constituting important energetic and kinetic benchmark and reference data, the results also help to understand the mechanisms of a number of very efficient electron-transfer processes in nature.

Nanoalloying effects and dealloying endow D-AgCuPd aerogels with significantly enhanced FOR activity compared to their monometallic, bimetallic and trimetallic counterparts.

The exploration and rational design of cost-effective, highly active, and durable catalysts for oxygen electrochemical reaction is crucial to actualize the prospective technologies such as metal−air batteries and fuel cells. Herein manganese cobalt oxide nanoparticles anchored on carbon nanofibers and wrapped in a nitrogen-doped carbon shell (MCO/ CNFs@NC) is successfully prepared. Benefiting from the synergistic effect between the core nanoparticles and nitrogen-doped carbon shell, MCO/CNFs@NC catalyst exhibits oxygen reduction reaction (ORR) activity with comparable onset potential (1.00 V vs RHE) and half-wave potential (0.76 V vs RHE) which is only about 40 mV lower than that of the state of art Pt/C catalyst. Furthermore, the MCO/CNFs@NC catalyst exceeds the Pt/C catalyst by a great margin in terms of stability in alkaline media. Additionally, MCO/CNFs@NC catalyst is strongly tolerant to methanol crossover, promising its applicability as cathode catalyst in alcohol fuel cells. Moreover, MCO/CNFs@NC catalyst exhibits the oxygen evolution reaction (OER) activity with low overpotential of 0.41 V at the current density of 10 mA cm −2 and ORR/OER potential gap (ΔE) as low as 0.88 V, suggesting its strong bifunctionality. The Zn−air battery based on MCO/CNFs@NC catalyst is found to deliver a specific capacity of 695 mA h g −1 Zn and an energy density of 778 W h kg −1 Zn at a current density of 20 mA cm −2 . The mechanically rechargeable Zn−air battery based on MCO/CNFs@NC catalyst is also found to function continually by only reloading the consumed Zn anode and electrolyte. Furthermore, the electrically rechargeable battery based on MCO/CNFs@NC catalyst is found to function for more than 220 cycles with negligible loss of voltaic efficiency. Moreover, MCO/CNFs@NC is found to display a supercapacitive nature with a good discharge capacity of 478 F g −1 at a discharge current density of 1 A g −1 .

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Incorporating an oxophilic metal into a noble metal to produce a cost-effective AgSn nanointermetallic catalyst is an emerging approach to enhance the catalytic activity of monometallic Ag in fuel cells, which is different from previous notions that consider a transition metal to increase the catalytic activity of Pt. The AgSn electrocatalyst is prepared by a facile electrodeposition method and exhibits high catalytic performance for the oxygen reduction reaction (ORR) and borohydride oxidation reaction (BOR). The AgSn electrocatalyst has an ORR specific activity of 0.246 mA cm, 1.3 times greater than the value of commercial Pt/C (0.187 mA cm) and a long-term stability with an 11 mV decrement in the half-wave potential and 7.01% loss of the diffusion-limiting current density after 2000 cycles, superior to that of Pt/C. Moreover, the AgSn electrocatalyst delivers a surprisingly higher BOR current density of 11.332 mA cm than most bimetallic Ag alloys. The better ORR catalytic activities of Ag-based alloys may arise from the ensemble effect, in which Sn atoms may promote the oxygen adsorption and Ag atoms may contribute to the removal of reaction products.

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The systems benzene/benzene-d(1) and o-/m-/p-difluorobenzene were studied in the dense gas phase with ultrafast transient absorption spectroscopy to investigate the effect of symmetry reduction through monodeuteration and constitutional isomerism on the timescales of intramolecular vibrational energy redistribution (IVR). In both systems IVR proceeds faster in the molecules of lower symmetry. In addition the dynamics were simulated in vibrational quantum number space using a simple model based on scaling state-to-state interactions by coupling order and the energy gap law. These simulations (semi-) quantitatively reproduce the experimental data for benzene and benzene-d(1) without incorporating further molecular symmetry restrictions. The relative impact of molecular symmetry and vibrational state space structure on IVR is discussed.