Green preparation of fiberboard waste derived N–doped carbon catalysts with tailored properties for efficient hydrogenation reduction of nitroaromatics

Abstract

Biomass–derived carbon materials doped with diverse heteroatoms have demonstrated huge potentials for environment and energy applications, thanks to the availability, preferable porous and channel structures, and excellent conductivity and stability. In this work, fiberboard waste containing resin–based adhesive was selected for the green fabrication of N–doped carbon catalysts without using extra N–sources. A facile two–step calcination strategy with sequential carbonization and activation was proposed for generation and exposure of indispensable active sites, realizing the controllable regulation of textural and morphological characteristics. The resulting N–doped fiberboard derived carbon (NFC) samples possessed unique hierarchically porous structures with a significantly enlarged surface area, plentiful activity–dependent N species (e.g., graphitic N and pyridinic N), as well as suitable graphitization degree and surface hydrophilicity. As a result, a favorable adsorption procedure and an enhanced accessibility of active sites synergistically boosted the catalytic performance towards hydrogenation reduction of nitroaromatics. Taking the NFC–hh sample as paradigm, an excellent performance was demonstrated for 4–nitrophenol (4–NP) reduction, achieving a high apparent rate constant of 0.40 min−1 and an impressive turnover frequency of ∼0.20 mmol g−1 min−1. Besides, the continuous–flowing catalytic test exhibited an excellent conversion efficiency > 99.50% with a long–term stability over 100 h, showing an attractive prospect for industrial application. This work presents a new approach for high value–added utilization of biomass waste, and provides a low–cost and high–active catalyst for environmental remediation.