| 1. |
- Yang, Biao, et al.
(författare)
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Abiotic Formation of an Amide Bond via Surface-Supported Direct Carboxyl-Amine Coupling
- 2022
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 61:5
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Tidskriftsartikel (refereegranskat)abstract
- Amide bond formation is one of the most important reactions in biochemistry, notably being of crucial importance for the origin of life. Herein, we combine scanning tunneling microscopy and X-ray photoelectron spectroscopy studies to provide evidence for thermally activated abiotic formation of amide bonds between adsorbed precursors through direct carboxyl-amine coupling under ultrahigh-vacuum conditions by means of on-surface synthesis. Complementary insights from temperature-programmed desorption measurements and density functional theory calculations reveal the competition between cross-coupling amide formation and decarboxylation reactions on the Au(111) surface. Furthermore, we demonstrate the critical influence of the employed metal support: whereas on Au(111) the coupling readily occurs, different reaction scenarios prevail on Ag(111) and Cu(111). The systematic experiments signal that archetypical bio-related molecules can be abiotically synthesized in clean environments without water or oxygen.
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| 2. |
- Zhang, Zhenzong, et al.
(författare)
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Internal electric field engineering step-scheme–based heterojunction using lead-free Cs3Bi2Br9 perovskite–modified In4SnS8 for selective photocatalytic CO2 reduction to CO
- 2022
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 313
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on improving photocatalytic CO2 reduction reaction (CRR) activity and modulating product selectivity. An In4SnS8/Cs3Bi2Br9-X (ISS/CBB-X) heterojunction is prepared using novel lead-free Cs3Bi2Br9 perovskite quantum dot–modified In4SnS8, which shows considerable potential as photocatalysts for CRRs under visible light. The optimised ISS/CBB photocatalyst exhibits high activity and CO selectivity with a CO yield and selectivity of 9.55 μmol g−1 h−1 and 92.9%, respectively, 3.8 and 1.5 times higher than those of pristine ISS, respectively. Moreover, the step-scheme (S-scheme) mechanism can be fully confirmed via in situ irradiated X-ray photoelectron spectroscopy, in situ electron spin resonance, femtosecond time-resolved absorption spectroscopy and density functional theory calculations. Based on in situ diffuse reflectance spectra and theoretical investigations, the ISS/CBB shows a decreased energy barrier towards CO2 reduction to CO through an adsorbed ⁕COOH intermediate. This study contributes to the further understanding of fabricating efficient S-scheme-based photocatalysts for selective CRR.
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