Real-Space Identification of Non-Noble Single Atomic Catalytic Sites within Metal-Coordinated Supramolecular Networks

Lammers BS, Lopez-Salas N, Siena JS, Mirhosseini H, Yesilpinar D, Heske J, Ku TD, Fuchs H, Antonietti M, Moenig H, Moenig H (2022)

Publication Type: Journal article

Publication year: 2022

Journal

ACS nano American Chemical Society

Book Volume: 16

Pages Range: 14284-14296

Journal Issue: 9

DOI: 10.1021/acsnano.2c04439

Abstract

With regard to the development of single atom catalysts (SACs), non-noble metal-organic layers combine a large functional variability with cost efficiency. Here, we characterize reacted layers of melamine and melem molecules on a Cu(111) surface by noncontact atomic force microscopy (nc-AFM), X-ray photoelectron spectroscopy (XPS) and ab initio simulations. Upon deposition on the substrate and subsequent heat treatments in ultrahigh vacuum (UHV), these precursors undergo a stepwise dehydrogenation. After full dehydrogenation of the amino groups, the molecular units lie flat and are strongly chemisorbed on the copper substrate. We observe a particularly extreme interaction of the dehydrogenated nitrogen atoms with single copper atoms located at intermolecular sites. In agreement with the nc-AFM measurements performed with an O-terminated copper tip on these triazine- and heptazine-based copper nitride structures, our ab initio simulations confirm a pronounced interaction of oxygen species at these N-Cu-N sites. To investigate the related functional properties of our samples regarding the oxygen reduction reaction (ORR), we developed an electrochemical setup for cyclic voltammetry experiments performed at ambient pressure within a drop of electrolyte in a controlled O2or N2environment. Both copper nitride structures show a robust activity in irreversibly catalyzing the reduction of oxygen. The activity is assigned to the intermolecular N-Cu-N sites of the triazine- and heptazine-based copper nitrides or corresponding oxygenated versions (N-CuO-N, N-CuO2-N). By combining nc-AFM characterization on the atomic scale with a direct electrochemical proof of performance, our work provides fundamental insights about active sites in a technologically highly relevant reaction.

Involved external institutions

Westfälische Wilhelms-Universität (WWU) Münster DE Germany (DE) Max-Planck-Institut für Kolloid- und Grenzflächenforschung / Max Planck Institute of Colloids and Interfaces DE Germany (DE) Universität Paderborn DE Germany (DE)

How to cite

APA:

Lammers, B.S., Lopez-Salas, N., Siena, J.S., Mirhosseini, H., Yesilpinar, D., Heske, J.,... Moenig, H. (2022). Real-Space Identification of Non-Noble Single Atomic Catalytic Sites within Metal-Coordinated Supramolecular Networks. ACS nano, 16(9), 14284-14296. https://dx.doi.org/10.1021/acsnano.2c04439

MLA:

Lammers, Bertram Schulze, et al. "Real-Space Identification of Non-Noble Single Atomic Catalytic Sites within Metal-Coordinated Supramolecular Networks." ACS nano 16.9 (2022): 14284-14296.

BibTeX: Download