Designing of Co3O4/N-doped carbon and Co-Co3O4/N-doped carbon nanomaterials via sol-gel route with unexpected high catalytic performances toward hydrogenation reduction of 4-Nitrophenol

Co3O4/N-doped carbon (Co3O4/NC) materials and Co-Co3O4/N-doped carbon materials were prepared by sol-gel method by using ethylene glycol (EG), glycerol or acrylamide as chelating agent and carbon source. The Co3O4/NC materials were obtained by calcination of the precursors at 500 & DEG;C, 600 ? or 700 ? in air by employing EG or glycerol as polymerization agent and urea as nitrogen source. The materials prepared at 500 & DEG;C by using EG and 600 ? by employing glycerol have excellent catalytic performance toward hydrogenation reduction reaction of 4-nitrophenol (4-NP) where NaHB4 has been used as reduction agent. High activity parameter per mass of oxide (K1 m) of 55.8 and 86.4 s-1.g-1, 108.9 and 157.3 s-1.g-1, 209.9 and 269.5 s-1.g-1, 333.4 and 617.1 s-1.g-1 could be obtained for the two materials prepared at 500 and 600 & DEG;C when the molar ratio of NaBH4 to 4-NP was 100:1, 200:1, 500:1 and 1000:1, respectively. Co-Co3O4/NC nanocatalyst was prepared by using acrylamide as sources of C and N without urea when the heating of the precursor was conducted at 600 ? under N2 protecting atmosphere, and high activity parameter (K1) values of 118.1 and 273.3 s-1.g-1 could be achieved when the molar ratio of NaBH4:4-NP was 100:1 and 1000:1. Our results provide new route for designing metal oxide/NC nanocatalysts with high catalytic performances. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, Co3O4/N-doped carbon materials and Co-Co3O4/N-doped carbon materials were prepared using the sol-gel method. Calcination and acid-base inhibition were employed to enhance the catalytic performance of the materials. The materials prepared using ethylene glycol and glycerol exhibited excellent catalytic activity in the hydrogenation reduction reaction. Additionally, using acrylamide as the source of carbon and nitrogen resulted in highly active Co-Co3O4/NC nanocatalysts.