Oxide reducibility is an important property in catalysis by metal-oxides. The reducibility of an oxide can be substantially modified when an interface is created between the oxide and a metal. Here we discuss two types of interfaces. One consists of gold nanoparticles deposited on anatase TiO₂ or tetragonal ZrO₂ (101) surfaces; these are traditional direct catalysts (metal deposited on an oxide). The second example consists of a metal support, Pt or a Pt₃Zr alloy, where a ZrO₂ nanofilm is deposited; this is representative of an inverse catalyst (oxide on metal). We designed models of these systems and analyzed by means of first principle calculations a key descriptor of the oxide reducibility, the cost of formation of an oxygen vacancy. We show that this cost is dramatically reduced when the oxide is interfaced with the metal. The effect on catalytic reactions is analyzed by computing the energy profiles for the CO oxidation reaction on Au/TiO₂ and Au/ZrO₂ model catalysts. Despite the very different nature of the two oxide supports, reducible for TiO₂ and non-reducible for ZrO₂, the same Au-assisted Mars–van Krevelen mechanism is found, with similar barriers.

氧化物的还原性是金属氧化物催化的重要性质。当在氧化物和金属之间形成界面时，可以实质上改变氧化物的还原性。在这里，我们讨论两种类型的接口。一种由沉积在锐钛矿型TiO ₂或四方ZrO ₂（101）表面上的金纳米颗粒组成；另一种由金纳米颗粒组成。它们是传统的直接催化剂（沉积在氧化物上的金属）。第二个示例由金属载体，Pt或Pt ₃ Zr合金组成，其中ZrO ₂沉积纳米膜；这代表了逆催化剂（金属上的氧化物）。我们设计了这些系统的模型，并通过第一性原理计算对氧化物还原性，形成氧空位的成本的关键指标进行了分析。我们表明，当氧化物与金属接触时，该成本将大大降低。通过计算Au / TiO ₂和Au / ZrO ₂模型催化剂上CO氧化反应的能量分布，分析了对催化反应的影响。尽管两种氧化物载体的性质非常不同（可被TiO ₂还原和不可被ZrO ₂还原），但发现了相同的金辅助的Mars-van Krevelen机理，具有相似的壁垒。