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Yang N, Zhu H, Sun X, Wu Y, Ding D, Chen Y. Surface-Immobilized ZnN x Sites as High-Performance Catalysts for Continuous Flow Knoevenagel Condensation in Water. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59502-59511. [PMID: 38086739 DOI: 10.1021/acsami.3c14181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
By immobilizing the metal complex on the substrate surface, our previous results have demonstrated that heterogeneous catalysts with well-dispersed active MNC (metal-nitrogen-carbon) sites can be prepared in a rational and efficient manner. In this study, we employed agarose aerogel (AA) as the substrate to illustrate a straightforward strategy for immobilizing ZnNx sites on the surface. Under relatively low temperatures, the amine group of the ligand condenses with the surface carbonyl group generated in situ, resulting in the surface immobilized Zn sites. This can be supported by the IR, PXRD, and XPS data. Comprehensive characterization methods, including synchrotron powder XRD and spherical aberration-corrected TEM, confirmed the absence of ZnNx site aggregation in the surface immobilization process, even with a high Zn content (up to 8 wt %). The immobilized ZnNx sites exhibited high catalytic performance in Knoevenagel condensation, and α,β-unsaturated compounds were obtained with high yield in both batch and continuous flow reactions. AA-ZnNx-200 showed the best catalytic activity, which was processed under 200 °C with a Zn content of 4.62 wt %. The immobilized ZnNx sites activated both the aldehyde and nitrile substrates, which were quantitatively converted into the corresponding α,β-unsaturated compounds, with water as the solvent at room temperature. In continuous flow reaction conditions, a conversion rate up to 99% can be achieved with malononitrile. This heterogeneous catalyst can be facilely produced with quantitative yield in a large scale from cheap starting material under mild conditions. No catalyst deactivation was observed after seven batch reaction cycles or 80 h of continuous flow reaction, indicating its high robustness under catalytic reaction conditions. This catalyst enables a separation-free, energy-saving, and environment-friendly production process, offering a practical way for the industrial production.
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Affiliation(s)
- Nan Yang
- College of Chemistry & Chemical Engineering, Central South University, Changsha, Hunan 410083, China
| | - Hongyan Zhu
- College of Chemistry & Chemical Engineering, Central South University, Changsha, Hunan 410083, China
| | - Xiaoxu Sun
- College of Chemistry & Chemical Engineering, Central South University, Changsha, Hunan 410083, China
| | - Yuewei Wu
- Shaanxi Electric Power Research Institute, Xi'an, Shanxi 710054, China
| | - De Ding
- Shaanxi Electric Power Research Institute, Xi'an, Shanxi 710054, China
| | - Yin Chen
- College of Chemistry & Chemical Engineering, Central South University, Changsha, Hunan 410083, China
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Hou Q, Liu K, Al-Maksoud W, Huang Y, Ding D, Lei Y, Zhang Y, Lin B, Zheng L, Liu M, Basset JM, Chen Y. Atomically Dispersed NiN x Site with High Oxygen Electrocatalysis Performance Facilely Produced via a Surface Immobilization Strategy. ACS APPLIED MATERIALS & INTERFACES 2023; 15:16809-16817. [PMID: 36972197 DOI: 10.1021/acsami.3c01228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Nonprecious-metal heterogeneous catalysts with atomically dispersed active sites demonstrated high activity and selectivity in different reactions, and the rational design and large-scale preparation of such catalysts are of great interest but remain a huge challenge. Current approaches usually involve extremely high-temperature and tedious procedures. Here, we demonstrated a straightforward and scalable preparation strategy. In two simple steps, the atomically dispersed Ni electrocatalyst can be synthesized in a tens grams scale with quantitative yield under mild conditions, and the active Ni sites were produced by immobilizing preorganized NiNx complex on the substrate surface via organic thermal reactions. This catalyst exhibits excellent catalysis performances in both oxygen evolution and reduction reactions. It also exhibited tunable catalysis activity, high catalysis reproducibility, and high stability. The atomically dispersed NiNx sites are tolerant at high Ni concentration, as the random reactions and metal nanoparticle formation that generally occurred at high temperatures were avoided. This strategy illustrated a practical and green method for the industrial manufacture of nonprecious-metal single-site catalysts with a predictable structure.
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Affiliation(s)
- Qiankun Hou
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China
| | - Kang Liu
- School of Physics and Electronic, Central South University, Changsha, Hunan 410083, People's Republic of China
| | - Walid Al-Maksoud
- Catalysis Centre, PSE, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Yuchang Huang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China
| | - De Ding
- Shaanxi Electric Power Research Institute, Xi'an, Shanxi 710054, People's Republic of China
| | - Yongpeng Lei
- Powder Metallurgy Research Institute, Central South University, Changsha, Hunan 410083, China
| | - Yi Zhang
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China
| | - Bin Lin
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
| | - Lirong Zheng
- Beijing Synchrotron Radiation Facility, Chinese Academy of Science, Institute of High Energy Physics, Beijing 100049, People's Republic of China
| | - Min Liu
- School of Physics and Electronic, Central South University, Changsha, Hunan 410083, People's Republic of China
| | - Jean-Marie Basset
- Catalysis Centre, PSE, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Yin Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, People's Republic of China
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