Identifying active sites of CoNC/CNT from pyrolysis of molecularly defined complexes for oxidative esterification and hydrogenation reactions

Abstract

Cobalt chelate complexes bonded to 2 to 3 nitrogens in the graphene lattice are the active sites for the oxidative esterification of benzyl alcohol by molecular oxygen, the selective reduction of nitrobenzene by hydrogen and the hydrogenated coupling of nitrobenzene and benzaldehyde.

Metal–Organic Framework Mediated Cobalt/Nitrogen‐Doped Carbon Hybrids as Efficient and Chemoselective Catalysts for the Hydrogenation of Nitroarenes

“…Bearing in mind the superior oxidation capacity of aqua regia, this is not surprising. Indeed, it has been reported by other authors that N‐doped graphene can be easily destroyed by acid treatment in concentrated HNO 3 , one of the main components of aqua regia . To gain more insight into the nature of the active sites in our Co@NC‐800 (al), a series of characterization measurements were performed.…”

“…Indeed, it has been reported by other authors that N-doped graphene can be easily destroyed by acid treatment in concentrated HNO 3 ,o ne of the main components of aqua regia. [14] To gain more insighti nto the nature of the active sites in our Co@NC-800 (al), as eries of characterization measurements werep erformed. The Raman and C1sX PS spectra of Co@NC-800 (al) ( Figure S4 Figure 3d)i sa lso observed.…”

“…Cheng et al. suggested that exposed cobalt nanoparticles do not play a role in the hydrogenation activity, and proposed that the real active sites are highly dispersed Co–N x species located in the carbon matrix . However, Liu et al.…”

“…Cheng et al suggested that exposed cobalt nanoparticles do not play ar ole in the hydrogenation activity,a nd proposed that the real active sites are highly dispersed Co-N x speciesl ocatedi nt he carbon matrix. [14] However, Liu et al indicated no detectable hydrogenation activity after acid leaching of aC o@Cc atalyst, and concluded that the hydrogenation activity is to be attributedt ot he accessible metallic cobalt NPs. [15] Similarly,W ang et al also did not detecta ny hydrogenation activity after leaching Co with aquar egia from aC o@NC catalyst using ZIF-67 as at emplate.…”

Cobalt-iron Oxide, Alloy and Nitride: Synthesis, Characterization and Application in Catalytic Peroxymonosulfate Activation for Orange II Degradation

“…The peaks at 397, 400.1, 402.7 and 404.7 eV could be assigned to the pyridinic, pyrrollic, graphitic N and oxidized pyridinic N [35,36]. The peak at 398.6 eV was ascribed to the pyridinic N coordinated with Fe or Co, i.e., N-Fe or N-Co, according to the literatures [36,37]. Less than 10% of graphitic N was found.…”