Comparative studies on catalytic behaviors of various Co- and Ni-based catalysts during liquid phase acetonitrile hydrogenation

Theoretical insight into the BH3·HCN adsorption on the Co(100) and Co(110) surfaces as hydrogen storage

Fifteen configurations and adsorption energies of the adsorption sites of BH₃∙∙∙HCN on Co(100) and Co(110) surfaces were investigated using the density functional theory. The results show that after BH₃∙∙∙HCN is adsorbed, although there is no general behavior for the H∙∙∙H distances, the adsorption energies of BH₃∙∙∙HCN are always far stronger than those of H₂ on Co surfaces, suggesting that the dihydrogen-bonded complex, one kind of prospective material for reversible hydrogen storage, can be tightly adsorbed on the surfaces of metals. Thus, the attempts to store the significant amounts of H₂ can be successful by the way that the dihydrogen-bonded complexes are adsorbed on the surfaces of metals. The stability and binding mechanism was analyzed by the Mulliken charge population and reduced density gradients (RDGs) methods. Graphical Abstract BH₃···HCN adsorption on Co surface.

Highly dispersive PdCoB catalysts for dechlorination of chlorophenols

Highly dispersive PdCoB nano-particles were prepared by precipitation-reduction with NaBH4 at 273 K. Characterization showed that the dispersion of amorphous alloy PdCoB nano-particles increased with decrease in both Pd/Co ratio and preparation temperature. The size of PdCoB-L(273) (Pd/Co ratio of 0.0005) nano-particles prepared at 273 K was 5 nm and BET specific surface area was estimated to be 177 m(2)/g, much higher than those of bimetallic catalysts reported in literature. During the hydrodechlorination of 4-chlorophenol, PdCoB catalysts were effective within pH range from 2.5 to 11. The activity of PdCoB can be promoted by the increase in B/Co ratio on the surface. PdCoB-L(273) sample presented the highest efficiency, and the reaction constants described in different terms for 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol were much higher than those obtained over PdFe in literature, probably ascribed to smaller particle sizes, less agglomerations and strong synergistic effect between Pd, Co and B species.

Isophthalonitrile (IPN) hydrogenation over K modified Ni–Co supported catalysts: catalyst characterization and performance evaluation

K modification suppressed both the original and the newly formed acid sites on the NiCo/Al₂O₃ catalyst, which were responsible for the condensation reactions in the IPN hydrogenation network.