Zhong Jian-Qiang, Shaikhutdinov Shamil, Roldan Cuenya Beatriz
Department of Interface Science, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany.
J Phys Chem C Nanomater Interfaces. 2021 Jan 21;125(2):1361-1367. doi: 10.1021/acs.jpcc.0c09382. Epub 2021 Jan 6.
We studied the initial stages of Ga interaction with the Cu(001) surface and environment-induced surface transformations in an attempt to elucidate the surface chemistry of the Cu-Ga catalysts recently proposed for CO hydrogenation to methanol. The results show that Ga readily intermixes with Cu upon deposition in vacuum. However, even traces of oxygen in the gas ambient cause Ga oxidation and the formation of two-dimensional ("monolayer") Ga oxide islands uniformly covering the Cu surface. The surface morphology and the oxidized state of Ga remain in H as well as in a CO + H reaction mixture at elevated pressures and temperatures (0.2 mbar, 700 K). The results indicate that the Ga-doped Cu surface under reaction conditions exposes a variety of structures including GaO /Cu interfacial sites, which must be taken into account for elucidating the reaction mechanism.
我们研究了镓与铜（001）表面相互作用的初始阶段以及环境诱导的表面转变，旨在阐明最近提出的用于一氧化碳加氢制甲醇的铜 - 镓催化剂的表面化学。结果表明，在真空中沉积时，镓很容易与铜混合。然而，即使气体环境中存在微量氧气也会导致镓氧化，并形成均匀覆盖铜表面的二维（“单层”）氧化镓岛。在高压和高温（0.2毫巴，700K）下，镓的表面形态和氧化态在氢气以及一氧化碳 + 氢气反应混合物中均保持不变。结果表明，在反应条件下，掺杂镓的铜表面暴露了包括GaO /Cu界面位点在内的多种结构，在阐明反应机理时必须考虑这些结构。
