A sustainable natural nanofibrous confinement strategy to obtain ultrafine Co3O4 nanocatalysts embedded in N-enriched carbon fibers for efficient biomass-derivative in situ hydrogenation

Abstract

Both exploring high-performance catalytic materials with ultrafine active sites from sustainable feedstocks and selective transformation of bio-renewable carboxides are very significant and challenging topics. Herein, we utilized bacterial cellulose to construct highly dispersed Co₃O₄ nanocatalysts embedded within nitrogen-doped carbon nanofibers (NCNFs). Benefiting from the nanofibrous confinement strategy, a urea-assisted carbonation process and a mild nitrate decomposition process, the cobalt precursor was transformed into ultrasmall and homogeneous Co₃O₄ nanoparticles (NPs) of ca. 1.57 nm, which is to our knowledge the smallest value among the reported supported Co₃O₄ materials. The as-obtained Co₃O₄/NCNF exhibits superior catalytic activity for the selective hydrogenation of bioderived α,β-unsaturated aldehydes with 2-propanol as a H-source, yielding 90–100% conversion under mild conditions. Controlled experiments and detailed characterization revealed that the three-dimensional nanofibrous porous structure can be favourable for improved diffusion and mass transfer, while the uniform distribution of ultrafine Co₃O₄ NPs and urea-derived abundant basic sites exhibit synergism in the adsorption and activation of reactants, which contributes to excellent catalytic performance. This approach opens up a new way to the design and fabrication of highly dispersed nanocatalysts based on NCNF materials from sustainable natural polymers for biomass valorization.