Carbon nanotube‐based titanium‐ and zirconium‐doped [M–N4] type ORR catalysts. First principle study. Issue 24 (27th August 2021)

• Record Type: Journal Article
• Authors: Kuzmin, Anton V.; Shainyan, Bagrat A.
• Is Part Of: International journal of quantum chemistry. Volume 121:Issue 24(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-27
• Subjects: carbon nanotubes -- DFT calculations -- nitrogen‐doped -- oxygen reduction reaction -- titanium -- zirconium; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26809
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: The efficiency of the Ti‐ and Zr‐doped nitrogen‐codoped carbon nanomaterials based on the (6, 6)armchair carbon nanotube C120 H24 with incorporated MN4 fragment has been analyzed using the first principle method at the DFT theory level. Two active sites on the catalyst surface have been revealed: the MN4 site and the adjacent NC═CN double bond (C2 site) of the support. A distinctive feature of Ti and Zr metals is that the MN4 site remains active even in the oxidized forms, although the C2 site becomes competitive. The free energy diagrams of the ORR were plotted for associative and dissociative mechanisms for both the initial and different oxidized forms in the acidic and alkaline media. The intermediates corresponding to the global minima were determined depending on the applied electrode potential and on the nature of the metal. Slightly lower exothermicity of oxygen adsorption and lower‐lying intermediates of the same type for Ti metal are indicative of some advantage of the Ti‐doped over the Zr‐doped MN4 –CNT catalysts. Abstract : The mechanism of oxygen electroreduction and its thermodynamics on the titanium‐ and zirconium‐doped nitrogen‐codoped CNT have been studied by means of DFT level of theory. Two active sites on the catalyst surface have been analyzed: the MN4 site and the NC═CN double bond (C2 site) of the support.