Carbon bead-supported nitrogen-enriched and Cu-doped carbon nanofibers for the abatement of NO emissions by reduction

Abstract

Carbon nanofibers (CNFs) were grown over highly porous (∼1750m2/g-surface area) carbon beads (∼0.8mm), using catalytic chemical vapor deposition (CVD). The carbon beads were produced by the pre-oxidation, carbonization and activation of the phenolic beads that were synthesized using the suspension polymerization. The beads were doped in situ with copper (Cu) during the polymerization reaction. The carbon beads decorated with the CNFs were treated with pyridine to increase the nitrogen (N) contents of the material. The N-enriched CNFs and Cu nanoparticles (NPs)-doped carbon beads (N–Cu–CNF/CBs) were used for the removal of nitric oxide (NO) by reduction. In its dual role, Cu catalyzed the growth of the CNFs during CVD, and also, the reduction reaction. Approximately 86% of NO conversion was achieved for 400ppm-NO concentration over 1g of the prepared catalyst at 500°C. The high catalytic activity was attributed to the combined roles of the Cu NPs, reactive CNFs and N-containing surface functional groups in the material. The prepared carbon bead-supported CNFs in this study are for the first time effectively used as the catalyst for the NO reduction without requiring ammonia or urea.