Cobalt Nanoparticles Embedded in N‐Doped Porous Carbon Derived from Bimetallic Zeolitic Imidazolate Frameworks for One‐Pot Selective Oxidative Depolymerization of Lignin

Abstract

Cobalt nanoparticles embedded in N‐doped porous carbon (Co@CN) were prepared by the pyrolysis of bimetallic zeolitic imidazolate frameworks (BMZIFs) based on ZIF‐8 and ZIF‐67. The catalyst shows excellent catalytic efficiency in one‐pot selective oxidative cleavage of different linkages like β‐O‐4, a‐O‐4 and β‐1 in organosolv lignin and lignin model compounds in the presence of oxygen (ambient pressure) under mild conditions (383 K). Compared with traditional supported catalyst, the catalyst gives a highly hollow structure, which favored the adsorption of substrates and oxygen. The uniform cobalt nanoparticles surrounded by N‐doped graphitic structures and the strong electron transfer from graphitic nitrogen to Co NPs make it hard to be oxidized prior to use and higher catalytic reactivity. Moreover, the catalyst can be easily recovered by magnetic force after the reaction, and reused after reduction for five times without an obvious change in yields.

Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C−N Framework Derived from the Integration of MOF and COF

“…All the synthesized C−N catalysts exhibit a broad XRD peak in the range of 15–30° (Figure 1A). The diffraction maxima of the broad reflection appear close to 25°, which are marginally deviated from the C (001) reflection known for a carbon material [37] . This suggests that the synthesized catalysts are graphitic [37] .…”

“…The diffraction maxima of the broad reflection appear close to 25°, which are marginally deviated from the C (001) reflection known for a carbon material. [37] This suggests that the synthesized catalysts are graphitic. [37] Diffraction peaks at 43.3°and 51.3°are observed for all the ZnCo-N@C catalysts indicating the presence of metallic Co species.…”

“…[37] This suggests that the synthesized catalysts are graphitic. [37] Diffraction peaks at 43.3°and 51.3°are observed for all the ZnCo-N@C catalysts indicating the presence of metallic Co species. 17 A weak diffraction peak around 36.5°is observed for the ZnCo-N@C (ZIF) , suggesting the presence of CoO in the ZnCo-N@C (ZIF) catalyst.…”

“…This is due to the volatile nature of Zn, which escapes from the materials during the carbonization process. [35,37] The surface Zn has more escaping tendency than the Zn incorporated in the CÀ N framework. The highresolution XPS spectra of Zn 2p show two deconvoluted peaks at 1044.7 eV and 1021.5 eV corresponding to the Zn 2p 1/2 and Zn 2p 3/2 of Zn-Nx species (Figure S7).…”

Green and sustainable route for oxidative depolymerization of lignin: New platform for fine chemicals and fuels

“…In recent years, significant development has been made in both homogeneous and heterogeneous transition metal-catalyzed lignin cleavage reactions and applied on lignin model compounds and extracted lignin successfully. [19][20][21] In real lignin, the presence of benzylic alcohol and respectively. But most of the current systems suffer with the harsh reaction conditions as they involve with high temperature and pressure.…”