CORRELATIONS BETWEEN THE PHYSICAL-CHEMICAL PROPERTIES AND CATALYTIC BEHAVIORS OF ALKALI-METAL GRAPHITE-INTERCALATION COMPOUNDS Academic Article uri icon

abstract

  • The catalytic behaviors of alkali metal-graphite intercalation compounds can be correlated with certain of the physical/chemical properties of these materials. The intrinsic activities of second-stage (MC24, M = K, Rb, or Cs) intercalates for ethylene hydrogenation and 1-butene isomerization at 40-70 C are markedly larger than those of their first-stage (MC8) counterparts, a behavior that is due to the much greater mobility and extent of ionization of alkali metal species in the former compounds. The differing strengths of metal-graphite bonding serve to categorize the various intercalates into two groups, based on their comparative abilities to form ternary second-stage compounds with hydrogen, and on the nature and extent of their interactions with oxygen and carbon monoxide. The metal-graphite bonding in Group I intercalates (KC8, KC24 and RbC8) is relatively weak; in consequence, upon exposure to O2 at 25 C or to CO at 200 C, these materials undergo extensive decomposition involving the expulsion of interplanar alkali metal species. This phenomenon results in marked decreases in activity for both ethylene hydrogenation and 1-butene isomerization, and in the preferential formation of C2+ hydrocarbons during CO hydrogenation. Group II intercalates (RbC24, RbC36, CsC8 and CsC24), on the other hand, because of stronger metal-graphite bonding, are not extensively decomposed by interaction with O2 or CO, and, as a result, produce primarily methane during CO hydrogenation. 1984.

published proceedings

  • JOURNAL OF MOLECULAR CATALYSIS

author list (cited authors)

  • ROSYNEK, M. P., & WANG, Y. P.

citation count

  • 2

complete list of authors

  • ROSYNEK, MP||WANG, YP

publication date

  • January 1984