Revealing the Influence of Silver in Ni–Ag Catalysts on the Selectivity of Higher Olefin Synthesis from Stearic Acid

Results on the conversion of stearic acid to olefins over Ni–Ag/γ-Al₂O₃ catalysts are presented. XANES and EXAFS experiments in situ and DFT calculations were applied to reveal the structure of active sites therein. It is shown that the introduction of Ag to Ni catalysts leads to an increase in the olefin yield. After a reduction in hydrogen (350°C, 3 h) alumina-supported nanoparticles of nickel sulfides and metallic Ag are formed. The role of metal hydrides formed during the reaction is extensively discussed.     

Reactivity of palladium(II) complexes supported on carbon toward molecular hydrogen

The reactivity of Pd(II) complexes supported on carbon toward H₂ was studied. For the carboxylate complexes Pd(RCOO)₂ (R = Me, Me₃C, F₃C), it decreases upon decrease in the basicity of the acid RCO₂H. The reactivity of Pd(II) η³-allyl complexes increases with increase in the Mulliken charges on the C atom of the allyl ligand connected to the substituent R. The results are in line with the heterocyclic mechanism of H-H bond activation in the hydrogen molecule and can be used for optimization of the composition of the initial compounds for the preparation of palladium catalysts.