Hydrogenation of ethylene over an LaNi5 plate

Ability of hydrogen storage CeNi5-x Ga x and Mg2Ni alloys to hydrogenate acetylene

Hydrogen storage properties and reactivity for hydrogenation of acetylene in a series of CeNi_5-x Ga _x (x = 0, 0.5, 0.75, 1, 1.25, 1.5) alloys and Mg₂Ni were determined and compared. The structure of CeNi₅ (CaCu₅ type) was maintained up to CeNi_3.5Ga_1.5 when Ni was replaced by Ga. The replacement facilitated hydrogenation absorption by creating larger interstitial spaces through expansion of the lattice, allowing CeNi_4.25Ga_0.75 to absorb the greatest proportion of hydrogen atoms among the alloys under the same conditions. The results showed that the absorbed hydrogen in CeNi_3.75Ga_1.25 improved reactivity. In contrast, Mg₂Ni formed a hydride upon hydrogenation of acetylene and thus possessed much lower activity. The difference of the activity of absorbed hydrogen between CeNi_5-x Ga _x and Mg₂Ni was confirmed from transient response tests under reaction gases alternately containing He and H₂.

CO2 Activation and Hydrogenation by PtHn (-) Cluster Anions

Gas phase reactions between PtHn (-) cluster anions and CO2 were investigated by mass spectrometry, anion photoelectron spectroscopy, and computations. Two major products, PtCO2 H(-) and PtCO2 H3 (-) , were observed. The atomic connectivity in PtCO2 H(-) can be depicted as HPtCO2 (-) , where the platinum atom is bonded to a bent CO2 moiety on one side and a hydrogen atom on the other. The atomic connectivity of PtCO2 H3 (-) can be described as H2 Pt(HCO2 )(-) , where the platinum atom is bound to a formate moiety on one side and two hydrogen atoms on the other. Computational studies of the reaction pathway revealed that the hydrogenation of CO2 by PtH3 (-) is highly energetically favorable.