Synergistic Catalysis of Co‐Zr/CNx Bimetallic Nanoparticles Enables Reductive Amination of Biobased Levulinic Acid

• Published in: Advanced sustainable systems (Online) 2022-03, Vol.6 (3), p.n/a
• Main Authors: Wu, Pei‐dong, Li, Hu, Fang, Zhen
• Format: Article
• Language: English
• Subjects: bimetallic synergy; biobased catalytic materials; biomass conversion; d‐band center; pyrrolidones
• ISSN: 2366-7486; 2366-7486
• DOI: 10.1002/adsu.202100321

Bimetallic synergy and carbon–nitrogen doping can contribute to enhanced catalytic activity due to the strong electronic state and unique geometrical structure. In this work, a series of biomass‐derived Co‐M bimetallic CN doped catalysts (Co‐M@Chitosan‐X; M = Zr, Ni, Fe, Cu, In; X denotes the molar percentage of M) are prepared via simple oil bath reflow and annealing. The Co‐Zr@Chitosan‐X catalysts are determined to contain alloys (Co‐Zr), metal‐carbon bonds (Co‐C, Zr‐C), metal‐nitrogen bonds (Co‐N, Zr‐N), and metal oxides (Co3O4, ZrO2) through a series of characterizations, in which graphite‐coated alloys and metal oxides are found to be the catalytically active species. The doping of the second metal results in a significant enhancement for the number of active sites in the catalyst, and the d‐band center is shifted toward a deviation from the Fermi energy level. Among the tested catalysts, Co‐Zr@Chitosan‐20 exhibits superior catalytic activity for the reductive amination of biobased levulinic acid to 5‐methyl‐2‐pyrrolidone in 99.3% selectivity and 92.8% yield. This non‐noble metal bimetallic synergistic catalytic protocol opens an avenue for efficiently producing biomass‐derived nitrogenous chemicals. A non‐noble bimetallic catalyst (Co‐Zr/CNx) is developed to be efficient for direct conversion of biobased levulinic acid to 5‐methyl‐2‐pyrrolidone in the green solvent H2O under mild conditions. The bimetallic nanoparticles play a synergistic role in the reductive amination process, and can maintain high activity over a long period of time in one‐pot reactions.