Metal clusters represent a promising class of catalysts for various reactions, but the simultaneous improvement of their stability and catalytic activity is a longstanding challenge. Herein, we created a stable dual-cluster metal-organic framework (MOF) that featured atomically synergistic bimetallic pair sites colocalized within sub-nanometer pockets. The pair sites, consisting of Ni and Mo sites respectively originating from defective MOF and Polyoxometalate (POM) clusters, were rationally constructed by size-matched ligand exchange. The as-obtained dual-cluster MOF (MnMo₆-lg-PCN-601) exhibited superior catalytic activity, rate performance (t_1/2 < 1 min, TOF = 140 min⁻¹), and stability toward the degradation of the chemical warfare agent simulant 2-chloroethyl ethyl sulfide (CEES). In-situ Fourier transform infrared (FTIR) studies and density functional theory (DFT) calculations demonstrated that the atomic synergy between colocalized pair sites favored the adsorption and activation of the CEES substrate, moreover, it also promoted H₂O₂ decomposition for the selective oxidation of CEES. Our work opens a new avenue for the construction of stable metal clusters with high catalytic activity for application in various multi-substrate reactions.

Spatial separation of oxidation/reduction cocatalyst is an effective means to improve the efficiency of charge separation in photocatalytic reaction systems. Herein, a yolk–shell Pd@NH₂-UiO-66@Cu₂O heterojunction was designed and synthesized by integration of electron collector Pd and hole collector Cu₂O inside and outside of a photoactive metal-organic framework (MOF) NH₂-UiO-66, respectively. The obtained Pd@NH₂-UiO-66@Cu₂O heterojunction effectively inhibits the electron and hole recombination through the photo-induced electrons and holes flow inward and outward of the composite, and promotes the reduction and oxidation abilities for the oxidative coupling of benzylamine to imines. Compared with Pd/NH₂-UiO-66@Cu₂O, Pd@NH₂-UiO-66, and Pd/NH₂-UiO-66, Pd@NH₂-UiO-66@Cu₂O exhibits the highest photocatalytic activity. More importantly, Pd@NH₂-UiO-66@Cu₂O shows a conversion rate of benzylamine up to 99% either by oxidation under aerobic conditions or by strong adsorption of H atom (H_ads) under anaerobic conditions. In addition, the catalyst shows good stability and can be recycled at least ten times. This work provides useful guidance on construction of MOFs-based composites with spatially separated photoinduced charge carriers to realize efficient oxidation coupling of benzylamine in both aerobic and anaerobic conditions.