Au/TiO₂ catalysts were produced by deposition-precipitation using different preparation conditions. Emphasis was laid on producing TiO₂ supports via oxalate precursors in the presence or absence of alkali and/or alkali-earth elements to vary on purpose the catalysts’ morphological state, surface composition and electronic structure. The home-made catalysts and a commercial Au/TiO₂ were analyzed in a comparative manner by mainly X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to identify the key parameters responsible for their high activity in the CO oxidation at room temperature. Among these parameters, which were strongly influenced by the catalyst preparation conditions, the abundance of reduced Ti³⁺ species was ascertained to be overarching along with the availability of negatively charged Au nanoparticles. The abundance of O 2p bonding orbitals in the valence band of TiO₂, which was modified by the presence of Au particles, and the extent of the support hydroxylation were also found to have a positive effect on the reaction rate. We further demonstrate that it is the specific area occupied by gold particles on the support surface that has to be taken into account to establish a reliable dependence of the reaction rate on the XPS-derived Au/Ti atomic ratio. All these factors have to be considered when assessing the activity performance of Au/TiO₂ catalysts prepared and activated according to different recipes. After-reaction studies, which were also performed with a selected home-made catalyst, show that a slight decrease in its catalytic activity with time-on-stream can be mainly attributed to an appreciable accumulation of various carbon-containing species on the support surface along with a loss of OH groups. In summary, we show that combined XPS/ToF-SIMS studies provide a reliable guide for tailoring the preparation of high-performance Au-supported catalysts.

通过使用不同的制备条件进行沉积沉淀来制备Au / TiO ₂催化剂。重点在于在存在或不存在碱和/或碱土元素的情况下，通过草酸盐前体生产TiO ₂载体，以有目的地改变催化剂的形态，表面组成和电子结构。主要通过X射线光电子能谱（XPS）和飞行时间二次离子质谱（ToF-SIMS），以比较方式对自制催化剂和市售Au / TiO ₂进行了分析，以找出造成该问题的关键参数。它们在室温下在CO氧化中具有很高的活性。在这些参数中，这些参数受催化剂制备条件的影响很大，其中还原钛的含量很高确定了³⁺物种以及带负电的Au纳米颗粒的可用性。发现TiO ₂价带中O 2p键合轨道的丰度（由于Au颗粒的存在而改变）和载体羟基化的程度也对反应速率产生积极影响。我们进一步证明，必须考虑到金颗粒在载体表面上所占的比表面积，才能确定反应速率对XPS衍生的Au / Ti原子比的可靠依赖性。在评估Au / TiO ₂的活性性能时必须考虑所有这些因素根据不同配方制备和活化的催化剂。反应后研究（也使用选定的自制催化剂进行）表明，其催化活性随时间的流逝而略有下降，这主要归因于各种含碳物质在载体表面上的明显积累。以及OH基团的丢失。总而言之，我们显示XPS / ToF-SIMS组合研究为定制高性能Au负载型催化剂的制备提供了可靠的指南。