PT  - JOURNAL ARTICLE
AU  - Johnson, A. D.
AU  - Daley, S. P.
AU  - Utz, A. L.
AU  - Ceyer, S. T.
TI  - The Chemistry of Bulk Hydrogen: Reaction of Hydrogen Embedded in Nickel with Adsorbed CH<sub>3</sub>
AID  - 10.1126/science.257.5067.223
DP  - 1992 Jul 10
TA  - Science
PG  - 223--225
VI  - 257
IP  - 5067
4099  - http://science.sciencemag.org/content/257/5067/223.short
4100  - http://science.sciencemag.org/content/257/5067/223.full
SO  - Science1992 Jul 10; 257
AB  - Studies in heterogeneous catalysis have long speculated on or have provided indirect evidence for the role of hydrogen embedded in the catalyst bulk as a primary reactant. This report describes experiments carried out under single-collision conditions that document the distinctive reactivity of hydrogen embedded in the bulk of the metal catalyst. Specifically, the bulk H atom is shown to be the reactive species in the hydrogenation of CH3 adsorbed on Ni(111) to form CH4, while the H atoms bound to the surface were unreactive. These results unambiguously demonstrate the importance of bulk species to heterogeneous catalytic chemistry.