The grand challenge in the development of atomically dispersed metallic catalysts is their low metal-atom loading density, uncontrollable localization and ambiguous interactions with supports, posing difficulty in maximizing their catalytic performance. Here, we achieve an interface catalyst consisting of atomic cobalt array covalently bound to distorted 1T MoS2 nanosheets (SA Co-D 1T MoS2). The phase of MoS2 transforming from 2H to D-1T, induced by strain from lattice mismatch and formation of Co-S covalent bond between Co and MoS2 during the assembly, is found to be essential to form the highly active single-atom array catalyst. SA Co-D 1T MoS2 achieves Pt-like activity toward HER and high long-term stability. Active-site blocking experiment together with density functional theory (DFT) calculations reveal that the superior catalytic behaviour is associated with an ensemble effect via the synergy of Co adatom and S of the D-1T MoS2 support by tuning hydrogen binding mode at the interface.

中文翻译：

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单原子钴阵列与畸变的1T MoS2结合在一起，具有整体作用，可催化氢逸出。

原子分散的金属催化剂开发中的最大挑战是它们的低金属原子装载密度，不可控制的局部化以及与载体的歧义相互作用，从而难以最大化其催化性能。在这里，我们实现了一种界面催化剂，该催化剂由与扭曲的1T MoS2纳米片（SA Co-D 1T MoS2）共价结合的原子钴阵列组成。发现MoS2从2H转变为D-1T的相，是由晶格失配引起的应变以及组装过程中Co和MoS2之间Co-S共价键的形成所诱导的，是形成高活性单原子阵列催化剂必不可少的。SA Co-D 1T MoS2对HER具有类似Pt的活性，并具有很高的长期稳定性。