The adsorption of CO in metal-organic framework CuBTC material is investigated by a combination of theoretical and experimental approaches. The adsorption enthalpy of CO on CuBTC determined experimentally to be -29 kJ mol(-1) at the zero-coverage limit is in very good agreement with the adsorption enthalpy calculated at the combined DFT-ab initio level with the periodic model. Calculations show that polycarbonyl complexes cannot be formed on regular coordinatively unsaturated sites in CuBTC. Experimental IR spectra of the CO probe molecule adsorbed in CuBTC are interpreted based on calculated CO stretching frequencies. Calculations show that long-range interactions are insignificant for the CO/CuBTC system and that this system can be accurately modeled with just a Cu(2)(HCOO)(4) cluster model of the paddle wheel. The reliability of various methods for the description of CO interaction with the Cu(2+) site in CuBTC is discussed based on the experimental results and accurate coupled-cluster calculations. It is shown that standard exchange-correlation functionals do not provide a reliable description of CO interaction with coordinatively unsaturated Cu(2+) sites in CuBTC.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/cphc.201100602 | DOI Listing |
ACS Nano
January 2025
Creative Research Initiative Center for Nanospace-confined Chemical Reactions (NCCR), Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
Unlike homogeneous metal complexes, achieving absolute control over reaction selectivity in heterogeneous catalysts remains a formidable challenge due to the unguided molecular adsorption/desorption on metal-surface sites. Conventional organic surface modifiers or ligands and rigid inorganic and metal-organic porous shells are not fully effective. Here, we introduce the concept of "ligand-porous shell cooperativity" to desirably reaction selectivity in heterogeneous catalysis.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Coordinatively unsaturated copper (Cu) has been demonstrated to be effective for electrifying CO reduction into C products by adjusting the coupling of C-C intermediates. Nevertheless, the intuitive impacts of ultralow coordination Cu sites on C products are scarcely elucidated due to the lack of synthetic recipes for Cu with low coordination numbers and its vulnerability to aggregation under reductive potentials. Herein, computational predictions revealed that Cu sites with higher levels of coordinative unsaturation favored the adsorption of C and C intermediates.
View Article and Find Full Text PDFMolecules
January 2025
Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
Rare earth phosphate (XPO) is an extremely important rare earth compound. It can exhibit excellent activity and stability in catalytic applications by modifying its inherent properties. Porous single-crystalline (PSC) PrPO and SmPO with a large surface area consist of ordered lattices and disordered interconnected pores, resulting in activity similar to nanocrystals and stability resembling bulk crystals.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, PR China.
Resolving the atomic surface structure, particularly surface termination or reconstruction, is essential for understanding the catalytic properties of metal oxides. Although rutile phase iridium dioxide (IrO) is the state-of-the-art electrocatalyst for the oxygen evolution reaction (OER) in water splitting, the atomic-level surface structures of IrO remain largely unexplored, limiting our understanding of its facet-dependent OER activities. Herein, we perform aberration-corrected integrated differential phase contrast scanning transmission electron microscopy of the low- and high-index surface structures of spindle-shaped IrO nanorods and reveal distinct surface terminations and/or reconstructions on different surfaces.
View Article and Find Full Text PDFNat Commun
January 2025
Brazilian Biorenewables National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.
Fatty acid peroxygenases have emerged as promising biocatalysts for hydrocarbon biosynthesis due to their ability to perform C-C scission, producing olefins - key building blocks for sustainable materials and fuels. These enzymes operate through non-canonical and complex mechanisms that yield a bifurcated chemoselectivity between hydroxylation and decarboxylation. In this study, we elucidate structural features in P450 decarboxylases that enable the catalysis of unsaturated substrates, expanding the mechanistic pathways for decarboxylation reaction.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!