Hydrogenation of carbon dioxide (CO₂) to produce fuels and value-added chemicals is a critical reaction to solve both energy and environment issues. Developing efficient catalysts composed of earth-abundant, cost-effective and eco-friendly elements is highly desired but remains challenging. Here, we exploit titanium-doped silicon cage nanoclusters (TiSi_n, n = 12–16) for CO₂ hydrogenation. Our first-principles calculations show that the activity and product selectivity of TiSi_n clusters exhibit remarkable size-dependences, and they can also absorb a large portion of sun light from visible to ultraviolet regimes to drive the catalysis. Their activity origins from the unsaturated electronic states on the silicon cage, mediated by the strong covalent bonding between Si and Ti atoms. More importantly, we establish a relationship between binding capability of TiSi_n clusters and the p orbital center of silicon cage, which provide general guidelines for atomically precise design of not only silicon-based clusters but also other non-metal catalysts for highly active and selective CO₂ conversion.

中文翻译：

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钛掺杂硅纳米笼上的太阳能驱动CO 2加氢

二氧化碳（CO ₂）的加氢生产燃料和增值化学品是解决能源和环境问题的关键反应。迫切需要开发由富含地球，具有成本效益和生态友好的元素组成的高效催化剂，但仍具有挑战性。在这里，我们利用掺杂钛的硅笼形纳米簇（TiSi _n，n  = 12–16）进行CO ₂加氢。我们的第一性原理计算表明，TiSi _n的活性和产物选择性团簇表现出显着的尺寸依赖性，它们还可以吸收从可见光到紫外光的大部分太阳光，以驱动催化作用。它们的活性源自硅笼子上的不饱和电子态，该状态由Si和Ti原子之间的强共价键介导。更重要的是，我们建立了TiSi _n团簇的结合能力与硅笼的p轨道中心之间的关系，这不仅为硅基团簇的原子精确设计提供了一般指导，还为高活性和选择性的其他非金属催化剂提供了原子精确设计CO ₂转化。