Pd clusters anchored on defect‐rich graphene enable efficient catalytic reduction of organic dyes in flow

Abstract Taking advantage of the relatively automatic and easy operation procedure, continuous‐flow catalysis has become a promising wastewater treatment technique for organic dye removal. However, developing suitable packing catalysts with favorable activity and low flow resistance remains a challenging task for the construction of continuous‐flow catalytic systems. In this paper, we report the preparation of a catalytic module, in which palladium clusters (Pd C ) are incorporated on defect‐rich nitrogen‐doped holey graphene (NHG) co‐assembled with aluminum silicate fibers (ASFs) (Pd C /NHG‐ASFs). The resultant Pd C /NHG‐ASFs composite catalyst exhibits an assembly morphology and can be facilely integrated into a glass reactor to construct an efficient fixed‐bed system for continuous‐flow catalysis. The corresponding catalytic system demonstrates high processing capacity and excellent durability for the reduction of six N‐containing organic dyes owing to the robust hierarchical structure and dual‐active components (i.e., NHG and Pd C ) of the Pd C /NHG‐ASFs composite. The processing rate of the fixed‐bed system constructed with the Pd C /NHG‐ASFs catalyst for the reduction of a representative dye (i.e., 4‐nitrophenol) was 1.45 × 10 −3 mmol·mg −1 ·min −1 , surpassing those previously reported for systems based on metal catalysts. Theoretical calculations show that the activity enhancement in nitroarene reduction reaction originate from the synergistic effect of the two active components. The integration of heterogeneous catalysis and flow‐chemistry techniques provides a rational design concept for environmental catalysis, offering a more efficient, scalable, and sustainable approach.