Cellulose filter paper (CFP) was modified with poly(acrylic acid) (PAA) and/or poly(ethylene glycol)methacrylate (PEGMA), followed by Cu immobilization for 4-nitrophenol (4NP) reduction. Among these samples, Cu-immobilized CFP modified with PEGMA polymer (CFP@PEGMA-Cu) exhibited the highest Cu incorporation of 2.21%. Those having the copolymer (CFP@PAA-co-PEGMA-Cu) demonstrated the highest efficiency, completing 4NP reduction in 3 min with an impressive 99.45% conversion, a high-rate constant (k) of 27.5 × 10−3 s−1, and turnover frequency (TOF) of 18.36 h−1. Notably, the catalysts containing PAA maintained good reusability, preserving 97% conversion upon 9 cycles. These results suggest their promising applications in sustainable catalysis, offering the catalytic potential with simple preparation and low cost required. [ABSTRACT FROM AUTHOR]