Progress in Post-modification of Framework Catalytic Materials at Shanghai Advanced Research Institute

Date : 2023-07-01

2023-06-29 Source: Shanghai Institute of Higher Studies

Recently, a researcher at the Shanghai Institute of Advanced Studies of the Chinese Academy of Sciences was at the summit of the Chinese Academy of Sciences.Associate ResearcherThe Xu Qing team has made important progress in adapting the Covalent Organic Framework (COFs) for the catalytic carbon dioxide reduction response. Relevant research findingsPost-synthetic modification of covalent organic frameworks for CO₂ electroreductionPublished in Nature-Communication.Nature CommunicationsGo on.

Catalyzed CO2 Reduction Response (CO)₂High-value products can be produced from greenhouse gases, providing strategies to address high CO2 emissions. Due to molecular designability, COFs are the ideal template for building CO2RR catalysts. COFs versus CO₂The catalytic behaviour of RR depends on its structure and nature. Structurally, different catalytic COFs are assembled through the type of catalytic centre, the electronic form of connective molecules and the diversity of connectors. The corresponding nature of COFs, e.g. CO, can be regulated by changing the building unit or connection key₂combined capacity and electronic conductivity. The meds boost CO.₂The ion-type framework can increase electroconductivity and the transfer of charge along the framework by integrating molecular capabilities. However, the direct synthesis of co-valent organic skeletons with a metamine key and ion-type framework is more difficult to achieve due to the limitations of electrostatic retort and bond strength.

Against this background, the team built COFs with methamid keys and ion skeletons through a double rearrangement method, and it achieved CO.₂High activity of RR and selectivity. Of these, the maximum efficiency of COfala was 97.32%, with a turnover rate of 9922.68 h^-1, above the original covalent organic skeleton and the monovalent covalent organic skeleton. In addition, theoretical calculations further indicate that the higher activity is attributable to the greater ease of production of *COOH* directly. The research is for the development of CO₂The co-priced organic framework, which responded back, provided new insights.

Research in CO₂Saturated KHCO₃Coco for catalytic COFs in aqueous solutions (0.5 M, pH 7.2)₂RR Performance. Research found through electrochemical tests in the range -0.5 ~ -1.0 V, N⁺– NH-COF FECO is 82.56 per cent, 88.76 per cent, 92.51 per cent, 97.32 per cent, 90.12 per cent and 82.78 per cent, respectively, and JCO is the highest in the -1.0 V range of 28.01 ma mc^-2, both higher than other COFs. In addition, as compared to other mono-modifications of COFs, N⁺-NH-COF displays higher TOF values and lower tafel slopes, indicating that multiple layers of rearmament improve COF CO₂RR activity and CO selectivity. In order to better understand the excellent catalytic behaviour of COFs, research is carried out to normalize current density by electrochemically active surface area. N⁺– COF and N.⁺The NH-COF ionization of COFs has always shown a higher contemplation of current density than CoTAPP-PATA-COF and NH-COF, confirming that ionization has helped to increase the activity of COF against CO2RR. The above-mentioned study demonstrated that the C-Namine key increased catalytic selectivity and the ion skeleton contributed to increased activity. In addition, theoretical calculations indicate M-I-N⁺– NH-COF’s *COOH-freedom changes the least and corresponds to its optimal performance from a thermodynamic point of view. TDOS shows that Co in M-I-N⁺-COF and M-I-N⁺The contribution of NH-COF is greater than that of M-CoTAPP-PATA-COF and M-NH-COF, indicating that the introduction of methyl bromide increases the electron density at the Co atom.

The study regulates the nature of COFs (pore, crystallization and electrostatic) through multi-post-modification strategies, helping them to regulate COFs.₂RR can be catalytic. Cofs-to-CO with ion skeletons and meds.₂RR is highly active and active. The work has made further progress in studying COFs and their applications in electrochemical storage and conversion systems. At the same time, it guides scientists to construct multi-layered synthesis and post-modification COFs to achieve customized activity and high stability.

The research is supported by the National Fund for Natural Sciences, the Shanghai City Science and Technology Council, the Youth Innovation Promotion Association of the Middle School of Science and Technology and the Henan Province High-level Internationalized Talent Development Fund. Research staff from the Shanghai University of Science and Technology and Henan Institute of Technology are involved in research.

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Figure 1. Multi-synthetic and post-modification maps

Figure 2. Electrochemical performance of four COFs

Figure 3. Theoretical calculations