Phenylphosphonic acid (PPA) adsorbed on Cu(111) has been studied by synchrotron radiation-based techniques in combination with density functional theory calculations. The dehydrogenated phenylphosphonic acid molecule (PP) strongly bound in a tridentate geometry through oxygen atoms to Cu(111) is shown to be the dominant surface species in the temperature range 150–300 °C. The stable PP adlayer substantially protects the Cu(111) surface from oxidation during exposure to ambient conditions. Thermal treatment of the PPA adlayer at 375 °C initiates molecular decomposition through several channels: P–O bond scission forming C₆H₅PO₂; C–P bond scission forming phenyl and PO₃; and C–H bond scission forming C₆H₄PO₃. All three reaction steps have activation barriers of 1.7–1.8 eV. Small products such as O, H, and phenyl can immediately react further and desorb, while the remaining phosphonate species undergo condensation. After annealing at a higher temperature, the phosphonate group is further reduced from oxygen-rich to phosphorus-rich species, which form the majority of remaining adsorbates after 500 °C treatment.

已通过基于同步辐射的技术结合密度泛函理论计算研究了吸附在 Cu(111) 上的苯基膦酸 (PPA)。脱氢苯基膦酸分子 (PP) 通过氧原子以三齿几何形状与 Cu(111) 强烈结合，在 150-300 °C 的温度范围内是主要的表面物质。在暴露于环境条件期间，稳定的 PP adlayer 可充分保护 Cu(111) 表面免受氧化。PPA 层在 375 °C 的热处理通过几个通道引发分子分解： P-O 键断裂形成 C ₆ H ₅ PO ₂；C-P键断裂形成苯基和PO ₃；和 C-H 键断裂形成 C ₆ H₄采购订单₃。所有三个反应步骤都具有 1.7-1.8 eV 的活化势垒。小产品如 O、H 和苯基可以立即进一步反应并解吸，而剩余的膦酸盐物质会发生缩合。在较高温度下退火后，膦酸酯基团从富氧物质进一步还原为富磷物质，在 500°C 处理后形成大部分剩余的吸附物。