Rational design of metal/N-doped carbon nanocatalysts via sol-gel method for obtaining high catalytic activity toward reduction reactions of 4-nitrophenol and Rhodamine B

This work reports main principles for designing metal/N-doped carbon (metal/NC) nanocatalysts via sol-gel method with high catalysis performances toward hydrogenation reduction reactions of 4-nitrophenol. Depending on standard electrode potentials of metallic ions, different kinds of polymerization agents should be selected. For designing Pd/NC, Pt/NC, Ni-Pd/NC nanocatalysts, starch can be selected as polymerization agent, and ethylene diamine tetraacetic acid is effective in designing Cu/NC nanocatalysts. For designing Ni/NC and Co/NC nanocatalysts, polyols, amines and amides, extracts of plant leaves can be used as polymerization agent. Nanocatalysts could be obtained when the dried precursors were calcined in the range of 350–700 °C under N2 atmosphere. By using NaBH4 as reducing agent, high activity parameter (per mass of metal) of 68.8 s−1·g−1, 597.1 s−1·g−1, 5571.7 s−1·g−1 can be obtained for Ni/NC, Cu/NC and Pd/NC nanocatalysts toward hydrogenation reaction of 4-nitrophenol. Our results provide new insight into designing and application of metal/N-doped carbon nanocatalysts. [Display omitted] •Metal/N-doped carbon (metal/NC) nanocatalysts can be prepared by sol-gel method.•Starch can be employed as polymerization agent for designing Pd/NC nanocatalysts.•EDTA can be used as polymerization agent for designing Cu/NC nanocatalysts.•Nanocatalysts have high catalytic performances toward hydrogenation of 4-nitrophenol.•Interface between metal nanoparticles and NC is identified to be catalytic center.