The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts c...The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.展开更多
Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the c...Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the capacity.While the molecular construct usually has a fixed dimension,whether its inter-molecular space could be self-adjustable during CO_(2)capture and release,behaving as a balloon,has captured imagination.Here we report a flexible intermolecular space of the double chain structure of self-assembled 1,4-pheny-lene diisocyanide(PDI)molecules on Ag(110)surface,which dynamically broadens and recovers during the CO_(2)capture and release.The incipient PDI double chains organize along the[001]direction of Ag(110),in which individual PDI molecules stand up in a zigzag order with the interchain width defined by twice the Ag lattice distance along_([110])direction(2α_([110])).When CO_(2)molecules are introduced,they assemble to occupy the interchain spaces,expanding the interchain width to 3α_([110]),4α_([110])and 5α_([110]):Warming up the sample leads to the thermally-driven CO_(2)desorption that recovers the original interchain space.High-resolution scanning tunneling microscopy(STM)jointly with density functional theory(DFT)calculations determine the structural and electronic interactions of CO_(2)molecules with the dynamical PDI structures,providing a molecular-level perspective for the design of a self-adjustable metal-organic construct for reversible gas capture and release.展开更多
文摘The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics.
基金supported by the Innovation Program for Quantum Science and Technology(2021ZD0303302)the CAS Project for Young Scientists in Basic Research(YSBR-054)+2 种基金the National Natural Science Foundation of China(Nos.22425206,21972129)NSF grant CHE-2303197the New Cornerstone Science Foundation.
文摘Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the capacity.While the molecular construct usually has a fixed dimension,whether its inter-molecular space could be self-adjustable during CO_(2)capture and release,behaving as a balloon,has captured imagination.Here we report a flexible intermolecular space of the double chain structure of self-assembled 1,4-pheny-lene diisocyanide(PDI)molecules on Ag(110)surface,which dynamically broadens and recovers during the CO_(2)capture and release.The incipient PDI double chains organize along the[001]direction of Ag(110),in which individual PDI molecules stand up in a zigzag order with the interchain width defined by twice the Ag lattice distance along_([110])direction(2α_([110])).When CO_(2)molecules are introduced,they assemble to occupy the interchain spaces,expanding the interchain width to 3α_([110]),4α_([110])and 5α_([110]):Warming up the sample leads to the thermally-driven CO_(2)desorption that recovers the original interchain space.High-resolution scanning tunneling microscopy(STM)jointly with density functional theory(DFT)calculations determine the structural and electronic interactions of CO_(2)molecules with the dynamical PDI structures,providing a molecular-level perspective for the design of a self-adjustable metal-organic construct for reversible gas capture and release.
