TY - JOUR
T1 - Dynamical behaviour of Pt‒Rh(100) alloy surface upon NO dissociation and NO + H2 reaction
AU - Hirano, H.
AU - Yamada, T.
AU - Tanaka, K.
AU - Siera, J.
AU - Nieuwenhuys, B. E.
N1 - Funding Information:
The authors acknowledge the Ministry of Economic Affairs of the Netherlands for their support of our collaboration program, and one of the authors (J Siera) worked at the ISSP of the University of Tokyo under the assistance of the Japan-Netherlands Institute. This work has been supported by the Ministry of Education of Japan by the Grant-in-aid (No. 01609003) for Scientific Research on Priority Area.
PY - 1990
Y1 - 1990
N2 - When a clean Pt-Rh(100) alloy surface was exposed to NO at T > 440K, the LEED pattern changed sequentially as p(1 × 1) → c(2 × 2) → c(2 × 2) + p(3 × 1) → p(3 × 1), where the c(2 × 2) pattern appeared immediately after the exposure to NO. Contrary to this, the formation of the p(3 × 1) needs some interval time which depends strongly on the initial Rh concentration of the alloy surface as adjusted by annealing in vacuum. When the p(3 × 1) surface was exposed to H2 by adding H2 to the NO gas, the AES intensity of O(a) decreased and while that of N(a) increased markedly. At the same time, the LEED pattern changed from p(3 × 1) to c(2 × 2). These results suggest that N(a) has equal affinity to the Pt and Rh sites on the alloy surface so that it is difficult for N(a) to distinguish the Pt and Rh atoms. On the other hand, O(a) prefers to make a stronger bond with Rh sites and prolonged exposure induces Rh surface segregation. The reaction of Rh atoms with O(a) on the Pt-Rh(100) surface yields a surface compound of p(3 × 1) structure.
AB - When a clean Pt-Rh(100) alloy surface was exposed to NO at T > 440K, the LEED pattern changed sequentially as p(1 × 1) → c(2 × 2) → c(2 × 2) + p(3 × 1) → p(3 × 1), where the c(2 × 2) pattern appeared immediately after the exposure to NO. Contrary to this, the formation of the p(3 × 1) needs some interval time which depends strongly on the initial Rh concentration of the alloy surface as adjusted by annealing in vacuum. When the p(3 × 1) surface was exposed to H2 by adding H2 to the NO gas, the AES intensity of O(a) decreased and while that of N(a) increased markedly. At the same time, the LEED pattern changed from p(3 × 1) to c(2 × 2). These results suggest that N(a) has equal affinity to the Pt and Rh sites on the alloy surface so that it is difficult for N(a) to distinguish the Pt and Rh atoms. On the other hand, O(a) prefers to make a stronger bond with Rh sites and prolonged exposure induces Rh surface segregation. The reaction of Rh atoms with O(a) on the Pt-Rh(100) surface yields a surface compound of p(3 × 1) structure.
UR - http://www.scopus.com/inward/record.url?scp=0025555124&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025555124&partnerID=8YFLogxK
U2 - 10.1016/S0042-207X(05)80138-1
DO - 10.1016/S0042-207X(05)80138-1
M3 - Article
AN - SCOPUS:0025555124
VL - 41
SP - 134
EP - 136
JO - Vacuum
JF - Vacuum
SN - 0042-207X
IS - 1-3
ER -