A comparative study of CCl4 reactions on Ag and Si surfaces by in situ ultraviolet photoemission electron microscopy

摘要

The reactivity of a bulk Ag surface, an Ag monolayer film on Si(111)-7 x 7 (denoted as the root 3 x root 3-Ag-Si surface), and Si(111)-7 x 7 to CCl4 was investigated by x-ray photoelectron spectroscopy (XPS) and ultraviolet photoemission electron microscopy (UV-PEEM). In situ UV-PEEM was used to monitor simultaneously the CCl4 dissociation on different surface domains, including the bulk Ag, root 3 x root 3-Ag-Si, and Si(111). The PEEM results combined with XPS data show that CCl4 adsorbs dissociatively on bulk Ag(111) and Si(111) but adsorbs molecularly on the root 3 x root 3-Ag-Si surface, and the surface reactivity follows the order of Si(111) > Ag(111) > root 3 x root 3-Ag-Si.