Revisiting H/Pt(111) by a combined experimental study of the H-D exchange reaction and first-principles calculations

查看全文 作　　者：XU [1]LingShun;MA [1]YunSheng;ZHANG [1]YuLin;TENG [2]BoTao;JIANG [1]ZhiQuan;HUANG [1]WeiXin 机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale; CAS Key Laboratory of Materials for Energy Conversion; Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China;[2]Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces; Institute of Physical Chemistry,Zhejiang Normal University,Jinhua 321004,China 出　　处：《Science China Chemistry》索引2011年第54卷第5期,共11页 基　　金：supported by the National Natural Science Foundation of China (NSFC20503027, NSFC20773113, NSFC20803072);the Ministry of Sci-ence and Technology of China, MOE Program for PCSIRT (IRT0756) 摘　　要：We report a detailed investigation of the behavior of chemisorbed hydrogen atoms (Ha) on Pt(111) by a combination of an ex-perimental study of the Ha + Da reaction and first-principles calculations. The coverage-dependent adsorption and desorption behavior of Ha and Da on Pt(111) have been systematically established and can be well interpreted in terms of repulsive inter-actions between adsorbates. Ha adsorbs exclusively on the face-centered cubic (fcc) sites of Pt(111) at coverages not exceeding 1 monolayer (ML). With increasing Ha coverage,repulsive interactions between Ha increase,leading to a reduction in both the adsorption energy and the desorption activation energy. It is proposed that the lateral interactions within a Ha layer are partly induced by the local repulsive interactions due to high mobility of Ha on Pt(111). For the Ha + Da exchange reaction on Pt(111),it is found that Ha has a higher selectivity for HD formation than Da. Considering that Ha diffuses much faster than Da on Pt(111),we propose that the difference in diffusion rates between Ha and Da may determine the selectivity of Ha and Da in forming HD in the Ha + Da reaction on Pt(111). 关 键 词：第一原理计算 交换反应 HD 实验 化学吸附 相互作用 面心立方 高流动性