Seyed Pouya Hosseini Yazdeli1,Andrés Rodríguez-Camargo2,Liang Yao2,Bettina Lotsch2,Kristina Tschulik3
Max-Planck-Institut für Eisenforschung1,Max Planck Institute for Institution Solid State Research Institution2,Ruhr-Universität Bochum3
Seyed Pouya Hosseini Yazdeli1,Andrés Rodríguez-Camargo2,Liang Yao2,Bettina Lotsch2,Kristina Tschulik3
Max-Planck-Institut für Eisenforschung1,Max Planck Institute for Institution Solid State Research Institution2,Ruhr-Universität Bochum3
Enhancing the efficiency and stability of catalysts for the oxygen evolution reaction (OER) is crucial for the advancement of renewable electrochemical energy conversion and storage technologies. The OER process, which plays a pivotal role in emerging technologies like water splitting, suffers from slow kinetics, leading to decreased overall device efficiency [1]. Addressing global energy and environmental challenges necessitates substantial research efforts in improving OER catalysts.<br/><br/>Covalent organic frameworks (COFs) offer great promise as a versatile class of materials with applications spanning multiple domains. These frameworks are constructed from light elements using reversible covalent bonds, resulting in crystalline structures characterized by high surface area, low density, and well-defined channels. Such properties render COFs suitable for a broad range of applications, including gas adsorption, chemical sensing, and heterogeneous catalysis. Furthermore, the facile functionalization of COFs grants them exceptional adaptability and versatility to cater to diverse requirements. [2]<br/><br/>In this study, we assessed the performance of a cobalt-modified bipyridine-based covalent organic framework (Co-TpBpy) as a heterogeneous catalyst for OER under alkaline conditions. To evaluate its effectiveness, we employed techniques such as voltammetry and differential electrochemical mass spectrometry (DEMS). Additionally, operando EC-SEIRAS experiments and post-mortem analyses involving TEM, XPS, XRD, and SEM-EDX were conducted to investigate the structural and compositional changes occurring during OER. The observations revealed the formation of cobalt oxide nanoparticles, serving as active sites for OER catalysis, embedded within the organic framework of Co-TpBpy. This phenomenon led to improved stability and catalytic performance. Our findings suggest that COFs can be utilized as templates to facilitate the uniform distribution of highly active cobalt oxide nanoparticles, thus enhancing the OER process.<br/><br/>References:<br/>[1] Y. Yan, B. Y. Xia, B. Zhao, X. Wang, J. Mater. Chem. A, 2016, 4, 17587.<br/>[2] J. Guo, D. Jiang, ACS Cent. Sci. 2020, 6