[2,1,3]-Benzothiadiazole-Spaced Co-Porphyrin-Based Covalent Organic Frameworks for O2 Reduction

Subhajit Bhunia; Armando Peña-Duarte; Huifang Li; Hong Li; Mohamed Fathi Sanad; Pranay Saha; Matthew A Addicoat; Kotaro Sasaki; T Amanda Strom; Miguel José Yacamán; Carlos R Cabrera; Ram Seshadri; Santanu Bhattacharya; Jean-Luc Brédas; Luis Echegoyen

doi:10.1021/acsnano.2c09838

[2,1,3]-Benzothiadiazole-Spaced Co-Porphyrin-Based Covalent Organic Frameworks for O₂ Reduction

ACS Nano. 2023 Feb 28;17(4):3492-3505. doi: 10.1021/acsnano.2c09838. Epub 2023 Feb 8.

Authors

Affiliations

¹ Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas79968, United States.
² College of Electromechanical Engineering, Qingdao University of Science and Technology, No. 99 Songling Road, Qingdao, Shandong266061, China.
³ Department of Chemistry and Biochemistry, The University of Arizona, 1041 East Lowell Street, Tucson, Arizona85721-0088, United States.
⁴ School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Kolkata700032, India.
⁵ Department of Chemistry and Forensics, Nottingham Trent University, Clifton Lane, NottinghamNG11 8NS, United Kingdom.
⁶ Chemistry Department, Brookhaven National Laboratory, Upton, New York11973, United States.
⁷ Materials Research Laboratory and Materials Department, University of California, Santa Barbara, California93106, United States.
⁸ Department of Applied Physics and Materials Science, Northern Arizona University, 525 South Beaver Street, Flagstaff, Arizona86011, United States.
⁹ Department of Organic Chemistry, Indian Institute of Science, Tala Marg, Bangalore560 012, India.

PMID: 36753696
DOI: 10.1021/acsnano.2c09838

Abstract

Designing N-coordinated porous single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) is a promising approach to achieve enhanced energy conversion due to maximized atom utilization and higher activity. Here, we report two Co(II)-porphyrin/ [2,1,3]-benzothiadiazole (BTD)-based covalent organic frameworks (COFs; Co@rhm-PorBTD and Co@sql-PorBTD), which are efficient SAC systems for O₂ electrocatalysis (ORR). Experimental results demonstrate that these two COFs outperform the mass activity (at 0.85 V) of commercial Pt/C (20%) by 5.8 times (Co@rhm-PorBTD) and 1.3 times (Co@sql-PorBTD), respectively. The specific activities of Co@rhm-PorBTD and Co@sql-PorBTD were found to be 10 times and 2.5 times larger than that of Pt/C, respectively. These COFs also exhibit larger power density and recycling stability in Zn-air batteries compared with a Pt/C-based air cathode. A theoretical analysis demonstrates that the combination of Co-porphyrin with two different BTD ligands affords two crystalline porous electrocatalysts having different d-band center positions, which leads to reactivity differences toward alkaline ORR. The strategy, design, and electrochemical performance of these two COFs offer a pyrolysis-free bottom-up approach that avoids the creation of random atomic sites, significant metal aggregation, or unpredictable structural features.

Keywords: alkaline oxygen reduction; benzothiadiazole based; covalent organic framework; donor−acceptor; porphyrin-benzothiadiazole; porphyrinic framework.