Nitrogen and oxygen-doped hollow carbon spheres with enhanced electrochemical capacitance were prepared via pyrolysis of poly(o-phenylenediamine) hollow submicrospheres.

The interaction of hydrogen with singly rhodium doped aluminum clusters AlnRh + (n = 1−12) is investigated experimentally by a combination of time-of-flight mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. Density functional theory (DFT) is employed to optimize the geometric and electronic structures of bare and hydrogenated AlnRh + clusters and the obtained infrared spectra of hydrogenated clusters are compared with the corresponding IRMPD spectra. The reactivity of the AlnRh + clusters towards H2 is found to be strongly size-dependent, with n = 1−3, and 7 being the most reactive. Furthermore, it is favorable for H2 to adsorb molecularly on Al2Rh + and Al3Rh + , while it prefers dissociative adsorption on other sizes. The initial molecular adsorption of H2 is identified as the determining step for hydrogen interaction with the AlnRh + clusters, because the calculated molecular adsorption energies of H2 correlate well with the experimental abundances of the hydrogenated clusters. Natural charge populations and properties of the AlnRh + clusters are analyzed to interpret the observed size-dependent reactivity.

Quantum confinement in small metal clusters leads to a bunching of states into electronic shells reminiscent of shells in atoms, enabling the classification of clusters as superatoms.

The interaction of hydrogen with Al_nRh₂⁺ (n = 10–13) clusters is studied by mass spectrometry and infrared multiple photon dissociation (IRMPD) spectroscopy. Comparing the IRMPD spectra with predictions obtained using density functional theory calculations allows for the identification of the hydrogen binding geometry. For n = 10 and 11, a single H₂ molecule binds dissociatively, whereas for n = 12 and 13, it adsorbs molecularly. Upon adsorption of a second H₂ to Al₁₂Rh₂⁺, both hydrogen molecules dissociate. Theoretical calculations suggest that the molecular adsorption for n = 12 and 13 is not due to kinetic impediment of the hydrogenation reaction by an activation barrier, but due to a higher binding energy of the molecularly adsorbed hydrogen–cluster complex. Inspection of the highest occupied molecular orbitals shows that the hydrogen molecule initially forms a strongly bound Kubas complex with the Al_11-13Rh₂⁺ clusters, whereas it only binds weakly with Al₁₀Rh₂⁺

Manganese oxide cluster anions (Mn m 16 O n ¯and Mn m 18 O n ¯) were prepared by laser ablation and reacted with hydrogen sulfide (H 2 S) in a fast flow reactor under thermal collision conditions. A time-of-flight mass spectrometer was used to detect the cluster distributions before and after interaction with H 2 S. The experiments suggest that an oxygen-for-sulfur (O/S) exchange reaction to release water occurred in the reactor for most of the manganese oxide cluster anions:The O/S exchange reactivity of Mn m O n ¯was generally found to decrease when the ratio (n/ m) of oxygen to manganese atoms in the cluster increased. Density functional theory (DFT) calculations were performed for reaction mechanisms of MnO 2 ¯+ H 2 S, MnO 3 ¯+ H 2 S, and Mn 2 O 4 ¯+ H 2 S. The computational results were in good agreement with the experimental observations. This gas-phase cluster study provides molecular-level insights into the adsorptive removal of H 2 S by bulk manganese oxides.

Vanadium oxide cluster cations (V m 16 O n + and V m 18 O n + ) are prepared by laser ablation and reacted with hydrogen sulfide (H 2 S) in a fast flow reactor under thermal collision conditions. A time-of-flight mass spectrometer is used to detect the cluster distributions before and after the interactions with H 2 S. The experiments suggest that, in addition to H 2 S adsorption to form association products V m O n H 2 S + , three types of reactions are evidenced in the reactor: (

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Transition metal oxide cluster anions M(m)(18)O(n)(-) (M = Fe, Co, Ni, Cu, and Zn) were prepared by laser ablation and reacted with H2S in a fast flow reactor under thermal collision conditions. A time-of-flight mass spectrometer was used to detect the cluster distributions before and after the interactions with H2S. The experiments reveal a suite of oxygen/sulfur (O/S) exchange and oxygen/sulfydryl (O/SH) exchange reactions. The O/S exchange reaction to release water was evidenced for all of the MO2(-) cluster anions: MO2(-) + H2S → MOS(-) + H2O, whereas the O/SH exchange reaction to derive MOSH(-) and OH species was only observed for reactions of NiO2(-), CuO2(-), and ZnO2(-). Density functional theory calculations were performed for reaction mechanisms of MO2(-) + H2S (M = Fe, Co, Ni, Cu, and Zn). The computational results are generally in good agreement with the experimental results. This gas-phase study provides an insight into the metal dependent reactivity in the removal of H2S over metal oxides.