Spatial confinement-stabilized copper single-atoms in amphiphilic zeolite for enhanced Fenton-like catalysis

Abstract

In Fenton-like reactions, simultaneously achieving both high activity and stability in single-atom catalysts remains challenging, and the limited accessibility of active sites further restricts efficiency. In this study, a Cu⁺ single-atom catalyst (Cu₂@amZ-200) with both high activity and stability is synthesized by utilizing the spatial confinement effect of zeolites. The TOF of Cu₂@amZ-200 is about 15.8 times higher than that of other similar catalysts in the degradation of methyl orange (MO) and no significant metal aggregation could be observed after at least 7 cycles. Benefiting from the amphiphilic functionalization, Cu₂@amZ-200 demonstrates a remarkable surface enrichment effect under static conditions, which effectively increases the local concentration of reactants and enables a 1.76-fold improvement in TOF compared to the unmodified catalyst. Experimental results and DFT calculations demonstrate that Cu+ exhibits the highest activity, and the ˙OH and ¹O₂ generated through the adsorption and activation of H₂O₂ play a dominant role. Notably, ¹O₂ broadens the effective pH range (2–10) for MO degradation, and its high selectivity toward electron-rich groups further accelerates the degradation process. This work proposes a new strategy for designing highly efficient and stable Fenton-like SACs, and establishes an environmentally friendly pure aqueous-phase catalytic system.