The new identity of cellulose pulp: A green silver nanoparticles support for highly efficient catalytic hydrogenation of 4-nitrophenol

Abstract

The uniquely interconvertible transformation of cellulose pulp and paper shows great potential as smart materials for environment remediation. However, performing liquid-phase catalytic reactions involving hydrogenation steps under mild conditions and ambient temperature remains challenging. Herein, we report a facile and eco-friendly strategy to fabricate low-cost, highly effective, and stable pulp-supported silver nanoparticles (AgNPs/pulp). The pulp phase is used to maintain the high catalytic efficiency of the AgNPs/pulp catalyst, while the paper phase remains high stability as the filling material in the reaction column. The as-prepared AgNPs/pulp catalyst exhibits excellent catalytic activity toward NaBH4-mediated reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a turnover frequency of 605.1 h−1 and a k value of 24.9 × 10−3 s−1 at room temperature, which outperforms most of reported cellulose-supported catalysts. Impressively, the AgNPs/pulp catalyst shows outstanding durability during a continuous operation for 72 h. Such excellent performance can be attributed to the uniform dispersion of the AgNPs/pulp in solution and uniform distribution of Ag NPs on the fiber surface of cotton pulp, which greatly improve the accessibility of reactants and active sites as well as metal-support interactions. This work provides new insights into the understanding of catalytic hydrogenation of 4-NP, which could pave the way for rational design of novel cellulose-based catalysts for organic wastewater treatment.