ADSORPTION OF HYDROGEN ON BE(0001) SURFACES

被引:33
作者
LOSSEV, V [1 ]
KUPPERS, J [1 ]
机构
[1] UNIV BAYREUTH,W-8580 BAYREUTH,GERMANY
关键词
D O I
10.1016/0039-6028(93)90535-R
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Molecular hydrogen does not adsorb on Be(0001) surfaces, suggesting activated adsorption, as was found with other s-metal/H adsorption systems. The present study investigates the interaction of thermal H atoms with clean and oxygen-covered Be(0001) surfaces using thermal desorption spectroscopy, TDS. Atomic hydrogen adsorbs at Be and oxygen-covered Be, at clean Be surfaces with a sticking coefficient in the order of unity. Molecular H-2 desorption is observed to follow a second-order rate at least in a restricted low coverage regime. Desorption is observed around 320 (O covered Be) and 450 K (clean Be) with activation energies of 14 and 20 (+/- 2) kcal/mol, respectively. Desorption frequency factors are obtained in the range 10(-4) cm2/s. At higher coverages the apparent desorption kinetics is different at Be and O-covered Be surfaces. The adsorption is endothermic with respect to H-2/Be and above 300 K hydrogen absorption in Be occurs competitively to desorption. Absorbed H in the Be bulk is outgassed with a complicated kinetics, however, H diffusion in Be seems not to limit H outgassing from Be. The formation of a Be-hydride is not observed.
引用
收藏
页码:175 / 185
页数:11
相关论文
共 28 条
[1]   DEUTERIUM PERMEATION AND DIFFUSION IN HIGH-PURITY BERYLLIUM [J].
ABRAMOV, E ;
RIEHM, MP ;
THOMPSON, DA ;
SMELTZER, WW .
JOURNAL OF NUCLEAR MATERIALS, 1990, 175 (1-2) :90-95
[2]  
ADAMS RO, STRUCT CHEM SOLID SU, V35, P70
[3]   ADSORPTION AND DESORPTION-KINETICS IN THE SYSTEMS H-2/CU(111), H-2/CU(110) AND H-2/CU(100) [J].
ANGER, G ;
WINKLER, A ;
RENDULIC, KD .
SURFACE SCIENCE, 1989, 220 (01) :1-17
[4]  
[Anonymous], 1968, METAL HYDRIDES
[5]  
BAGUS PS, 1983, CHEM PHYS, V78, P1930
[6]   MOLECULAR-BEAM STUDY OF APPARENT ACTIVATION BARRIER ASSOCIATED WITH ADSORPTION AND DESORPTION OF HYDROGEN ON COPPER [J].
BALOOCH, M ;
CARDILLO, MJ ;
MILLER, DR ;
STICKNEY, RE .
SURFACE SCIENCE, 1974, 46 (02) :358-392
[7]  
Barin I., 1973, THERMOCHEMICAL PROPE
[8]   AN INVESTIGATION OF VIBRATIONALLY ASSISTED ADSORPTION - THE CASES H-2/CU(110) AND H-2/AL(110) [J].
BERGER, HF ;
RENDULIC, KD .
SURFACE SCIENCE, 1991, 253 (1-3) :325-333
[9]   INTERACTION OF HYDROGEN WITH SOLID-SURFACES [J].
CHRISTMANN, K .
SURFACE SCIENCE REPORTS, 1988, 9 (1-3) :1-163
[10]   DYNAMICAL PARAMETERS OF DESORBING MOLECULES [J].
Comsa, George ;
David, Rudolf .
SURFACE SCIENCE REPORTS, 1985, 5 (04) :145-198