基于密度泛函理论考察勃姆石（AlOOH）和氧化锆（ZrO2）负载的钯团簇表面氢分子吸附和解离吸附过程，通过分析一系列不同尺寸的钯团簇上氢吸附能以及氢分子-钯团簇-载体三者之间的电荷转移系统地研究了粒径效应和载体效应。结果表明，顶点位和面位分别是分子吸附和解离吸附的最佳吸附位置。随着钯团簇粒径的上升，氢分子吸附能和解离吸附能都下降，载体-钯团簇-被吸附氢三者之间的电荷转移量和方向也改变。氧化锆载体负载的钯团簇上分子吸附能和解离吸附能均大于勃姆石载体负载的钯团簇，说明载体对氢分子吸附过程有重要影响。%Molecular and dissociative adsorption of hydrogen at PdN clusters (N=1, 4, 8, 13) supported on AlOOH and ZrO2 were investigated using density functional theory. Effects of cluster size and carrier were assessed through study of hydrogen adsorption energies and electron transfers among carrier, PdN cluster and adsorbed hydrogen. Molecular adsorption occurred preferentially at atop sites of the supported PdN clusters while dissociative adsorption favored face sites. With the increase of cluster size, both molecular and dissociative adsorption energies decreased as well as both amount and direction of electron transfer among carrier, PdN clusters and adsorbed hydrogen altered. The molecular and dissociative adsorption energies on ZrO2 supported PdN clusters were higher than those on AlOOH supported PdN clusters, indicating that carrier was also important to hydrogen adsorption.
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