Co3O4 anchored in N, S heteroatom co-doped porous carbons for degradation of organic contaminant: role of pyridinic N-Co binding and high tolerance of chloride

• Published in: Applied catalysis. B, Environmental Vol. 282; p. 119484
• Main Authors: Peng, Lijing, Shang, Yanan, Gao, Baoyu, Xu, Xing
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-03-2021; Elsevier BV
• Subjects: Active sites; Binding; Chloride; Chlorides; Cobalt oxides; Contaminants; Degradation; Heteroatoms; Nanoparticles; Nitrogen; Organic contaminants; Paracetamol; Peroxymonosulfate; Pyrolysis; Sulfur; Paracetamol; Chloride; Peroxymonosulfate; Heteroatoms
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119484

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•Pyridinic N is more easily to coordinate with Co3O4 nanoparticles embedded in carbon.•Pyridinic N-Co binding was the dominant catalytic sites for PMS activation.•A large amount of HClO was generated from the direct reaction of Cl- with PMS.•Higher HClO intensity was observed in Co3O4@NSC/PMS/Cl- system.
In this work, Co3O4 embedded nitrogen and sulfur co-doped porous char (Co3O4@NSC) was prepared after one-pot pyrolysis of N, S in-rich rubber powder (RP) to determine the binding relationship between Co nanoparticles and multiple doped heteroatoms. Results indicated pyridinic N was more easily to coordinate with Co3O4 nanoparticles, forming the pyridinic N-Co binding in Co3O4@NSC, which was the dominant catalytic sites for peroxymonosulfate (PMS) activation. Paracetamol (PCM) degradation was greatly facilitated with Cl- surrounding in Co3O4@NSC/PMS system due to the formation of large amounts of HOCl generated from the direct reaction of Cl- with PMS. The Cl↓ serving as a precursor of HOCl by reacting with PMS can be further strengthened by pyridinic N-Co bindings in Co3O4@NSC than the NSC. As a result, the pyridinic Co-N sites not only acted as the essential catalytic sites for PMS activation, but also accelerated the formation of HOCl at high level of Cl-.