摘要
应用 HREELS和 TDS研究了 1 2 0 K时 CO在轻微氧化的 Mo( 1 0 0 )上的吸附和脱附状况 .1 2 0 K时 ,CO在轻微氧化的 Mo( 1 0 0 )上存在顶位垂直吸附 ( νCO=2 0 1 6～ 2 0 50 cm- 1 )、四重空位倾斜吸附 ( νCO=1 0 88cm- 1 )和通过 π键与表面发生作用的倾斜吸附 ( νCO=1 60 0 cm- 1 ) .当表面温度升高时 ,顶位吸附的 CO在低覆盖度下发生解离 ,但在较高覆盖度下 ,可以同时发生脱附 ( Tp=3 1 9K)和解离 ;而后两种吸附态在温度升高时只发生解离 .CO解离产生的 C原子和 O原子在 93 0 K和 1 3 2 0 K时可重新结合成
The adsorption and desorption of CO on the slightly oxidized Mo(100) surface at 120 K were studied by HREELS and TDS. It was found that three CO molecular states existed on the slightly oxidized Mo(100) surface at 120 K, namely CO terminally bonded on a top sites ( CO =2 016—2 050 cm -1 ), bonded in four fold hollow sites with a tilted geometry ( CO =1 088 cm -1 ) and bonded in an inclined manner to a Mo atom through the carbon end and further coordinated to another Mo atom through a π CO bond ( CO =1 600 cm -1 ) respectively. For the terminally bonded CO, heating the surface induced the dissociation at lower coverage. At the higher coverage, however, heating the sample caused the dissociation occurring below 450 K and desorption( T p=319 K) simultaneously. For other two CO states, only dissociation could be detected during heating the surface. The chemisorbed carbon and oxygen atoms produced from CO dissociation could be recombined to form CO to leave the surface at 928 and ~1 320 K. [WT5HZ]
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第4期601-604,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金! (批准号 :2 9873 0 42 )
催化基础国家重点实验室资助
