Heterogeneous catalysts are highly complex materials with respect to both their compositions and structures.The development of heterogeneous catalysts with optimized performances requires the fine-tuning of various factors,such as the composition,size and shape of the metals,and the unique properties of supports or other promoters,many of which play important but often incompletely understood roles in determining overall activity and stability of the catalysts.In the past decades,surface science has made valuable contributions to the understanding of catalysis with the Heterogeneous catalysts are highly complex materials with respect to both compositions and structures. The development of heterogeneous catalysts with optimized performances require the fine-tuning of various factors, such as the composition, size and shape of the metals, and the unique properties of supports or other promoters, many of which play important but often incompletely roles in defining overall activity and stability of the catalysts. In the past decades, surface science has made valuable contributions to the understanding of catalysis with the