Although non-noble metal catalysts are appealing for propane dehydrogenation, achieving high propylene selectivity remains a persistent challenge, which necessitates the regulation of catalytic microenvironment. In this study, we comparatively investigate three commonly used active metals (Pt, Pd, and non-noble metal Ni) using both theoretical and experimental approaches. We find that the low selectivity of Ni-based catalysts is intrinsically attributed to a narrow interatomic distance (Δd) between Ni atoms, which promotes side reactions. Thus, Ni-based intermetallic alloys are employed to modulate Δd, whose surface microenvironment is quantified with a descriptor called degree-of-isolation. The established volcano-shaped isolation-selectivity plot provides a direct avenue for predicting propylene selectivity, which is determined by two competing variables: desorption and further dehydrogenation of propylene. The optimal catalyst, NiIn, manifests moderate Ni–C repulsion, obtaining >91% experimental propylene selectivity. This reveals the Sabatier principle over Ni-based catalysts for selective propane dehydrogenation and underscores the significance of microenvironment engineering.

中文翻译：

---

用于选择性丙烷脱氢的非贵金属合金的微环境工程


尽管非贵金属催化剂对丙烷脱氢很有吸引力，但实现高丙烯选择性仍然是一个持续的挑战，这需要对催化微环境进行调节。在这项研究中，我们使用理论和实验方法对三种常用的活性金属 （Pt、Pd 和非贵金属 Ni） 进行了比较研究。我们发现，Ni 基催化剂的低选择性本质上归因于 Ni 原子之间的原子间距离 （Δd） 狭窄，这促进了副反应。因此，镍基金属间化合物合金被用来调制 Δd，其表面微环境用称为隔离度的描述符来量化。建立的火山形分离-选择性图为预测丙烯选择性提供了直接途径，丙烯选择性由两个竞争变量决定：丙烯的解吸和进一步脱氢。最佳催化剂 NiIn 表现出适度的 Ni-C 排斥性，获得 >91% 的实验丙烯选择性。这揭示了 Sabatier 原理优于 Ni 基催化剂的选择性丙烷脱氢，并强调了微环境工程的重要性。