Hamburg 2001 – scientific programme
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O: Oberflächenphysik
O 21: Oberfl
ächenreaktionen (II)
O 21.5: Talk
Tuesday, March 27, 2001, 17:15–17:30, B
The Adsorption of Hydrogen on the RuO2(110) Surface — •J. Wang, C. Y. Fan, K. Jacobi, and G. Ertl — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin
The adsorption of hydrogen on RuO2(110) was studied by TDS and HREELS. Two adsorption states of hydrogen (α-H and β-H) were observed. α-H is rather weakly bonded and desorbs already at 100 K in a rather sharp TD spectrum. As there is nearly no isotope exchange with D in this state, one has to conclude that the two H-atoms sit very near to each other and that exchange with nextnearest D atoms does not take place. Any anticipated ν(H-H) mode for chemisorbed molecular hydrogen could not be observed. β-H adsorbs dissociatively and desorbs at 270...330 K. A rather high-energetic vibration mode is observed at 231 meV, which may be assigned to a rather directed bond to the coordinatively unsaturated Ru surface atom. Besides H2 desorption we observe also H2O formation giving rise to two desorption peaks at 370 and 550 K. The latter one is assigned to OH disproportionation, since we observe the formation of OH at intermediate temperatures.