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- Hu, Qiyu, et al.
(författare)
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Advances in bridging homogeneous and heterogeneous water oxidation catalysis by insolubilized polyoxometalate clusters
- 2024
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 14:8, s. 5898-5910
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Forskningsöversikt (refereegranskat)abstract
- The water oxidation half-reaction is vital in numerous alternative-energy blueprints and technologies since it can provide four protons and four electrons necessary for transforming renewable energy into chemicals and fuels. Significant progress has been made in recent decades in regard to the development of heterogeneous and homogeneous water oxidation catalysts (WOCs). However, homogeneous and heterogeneous catalysts are two parallel frontiers in catalysis science, each possessing their individual advantages and disadvantages. It is urgently required to construct desirable catalysts combining the merits and overcoming the natural shortcomings of homogeneous and heterogeneous WOCs. This Perspective demonstrates an overview of recent progress in utilizing insoluble polyoxometalate (POM) clusters as a promising bridge between homogeneous and heterogeneous WOCs and discusses the characterization methods for the stability, the origin of enhanced activities, electron transfer dynamics, and structure-property correlation of insoluble POM cluster WOCs. This Perspective not only guides the design of robust and efficient insoluble POM cluster catalysts applied for energy transformation but also provides important insights into the design of POM-based heterogeneous catalysts applied in other important fields.
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| 2. |
- Hu, Qiyu, et al.
(författare)
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Developing insoluble polyoxometalate clusters to bridge homogeneous and heterogeneous water oxidation photocatalysis
- 2023
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 2:32
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Tidskriftsartikel (refereegranskat)abstract
- Cluster catalysts are attractive for their atomically precise structures, defined compositions, tunable coordination environments, uniform active sites, and their ability to transfer multiple electrons, but they suffer from poor stability and recyclability. Here, we report a general approach to the direct insolubilization of a water soluble polyoxometalate (POM) [{(B-α-PW9O34)Co3(OH)(H2O)2(O3PC(O)-(C3H6NH3)PO3)}2Co]14- (Co7) and formation of a series of POM-based solid catalysts with the counter-cations Ag+, Cs+, Sr2+, Ba2+, Pb2+, Y3+, and Ce3+. They exhibit improved catalytic activities for visible-light-driven water oxidation following the trend CsCo7>SrCo7>AgCo7>CeIII Co7>BaCo7>YCo7>PbCo7. While CsCo7 exhibits mainly homogeneous catalysis, the others are predominantly heterogeneous catalysts. An optimal oxygen yield of 41.3 % and a high apparent quantum yield (AQY) of 30.6 % for SrCo7 is obtained, which is comparable to that of the parent homogeneous POM. Band gap structures, UV/Vis spectra, and real-time laser flash photolysis experiments collectively suggest that easier electron transfer from the solid POM catalyst to the photosensitizer promotes photocatalytic water oxidation performance. These solid POM catalysts exhibit good stability, which is directly confirmed by a combination of Fourier-transform infrared spectroscopy, electron microscopy, X-ray diffraction patterns, Raman spectroscopy, X-ray photoelectron spectroscopy, five cycles of tests, and poisoning experiments.
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| 4. |
- Zhang, Juqing, et al.
(författare)
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Super-enhancers conserved within placental mammals maintain stem cell pluripotency
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 119:40
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Tidskriftsartikel (refereegranskat)abstract
- Despite pluripotent stem cells sharing key transcription factors, their maintenance involves distinct genetic inputs. Emerging evidence suggests that super-enhancers (SEs) can function as master regulatory hubs to control cell identity and pluripotency in humans and mice. However, whether pluripotency-associated SEs share an evolutionary origin in mammals remains elusive. Here, we performed comprehensive comparative epigenomic and transcription factor binding analyses among pigs, humans, and mice to identify pluripotency-associated SEs. Like typical enhancers, SEs displayed rapid evolu-tion in mammals. We showed that BRD4 is an essential and conserved activator for mammalian pluripotency-associated SEs. Comparative motif enrichment analysis revealed 30 shared transcription factor binding motifs among the three species. The majority of transcriptional factors that bind to identified motifs are known regulators associated with pluripotency. Further, we discovered three pluripotency-associated SEs (SE-SOX2, SE-PIM1, and SE-FGFR1) that displayed remarkable conservation in pla-cental mammals and were sufficient to drive reporter gene expression in a pluripotency-dependent manner. Disruption of these conserved SEs through the CRISPR-Cas9 approach severely impaired stem cell pluripotency. Our study provides insights into the understanding of conserved regulatory mechanisms underlying the maintenance of plu-ripotency as well as species-specific modulation of the pluripotency-associated regula-tory networks in mammals.
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