Selective Hydrogenation on a Highly Active Single-Atom Catalyst of Palladium Dispersed on Ceria Nanorods by Defect Engineering

AbstractPursuing and developing effective methodologies to construct highly active catalytic sites to maximize the atomic and energy efficiency by material engineering are attractive. Relative to the tremendous researches of carbon-based single atom systems, the construction of bio-applicable single atom materials is still in its infancy. Herein, we propose a facile and general interfacial-confined coordination strategy to construct high-quality single-atom nanotherapeutic agent with Fe single atoms being anchored on defective carbon dots confined in a biocompatible mesoporous silica nanoreactor. Furthermore, the efficient energy conversion capability of silica-based Fe single atoms system has been demonstrated on the basis of the exogenous physical photo irradiation and endogenous biochemical reactive oxygen species stimulus in the confined mesoporous network. More importantly, the highest photothermal conversion efficiency with the mechanism of increased electron density and narrow bandgap of this single atom structure in defective carbon was proposed by the theoretical DFT calculations. The present methodology provides a scientific paradigm to design and develop versatile single atom nanotherapeutics with adjustable metal components and tune the corresponding reactions for safe and efficient tumor therapeutic strategy.

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Post Synthetic Defect Engineering of UiO-66 Metal-Organic Framework with Iridium(III)-HEDTA Complex and Application in Catalysis for Water Oxydation

10.20944/preprints201908.0141.v1 ◽

2019 ◽

Author(s):

Ferdinando Costantino ◽

Alceo Macchioni ◽

Giordano Gatto ◽

Roberto Bondi ◽

Fabio Marmottini

Keyword(s):

Water Oxidation ◽

Metal Organic Framework ◽

Partial Substitution ◽

Iridium Complexes ◽

Defect Engineering ◽

Cerium Ammonium Nitrate ◽

Highly Active ◽

Metal Organic ◽

Heterogenous Catalyst ◽

Sacrificial Agent

Clean production of renewable fuels is a great challenge of our scientific community. Iridium complexes have demonstrated a superior catalytic activity in the water oxidation (WO) reaction, which is a crucial step in water splitting process. Herein we have used a defective zirconium MOF with UiO-66 structure as support of a highly active Ir complex based on EDTA with formula [Ir(HEDTA)Cl]Na. The defects are induced by the partial substitution of tereftalic acid with smaller formiate groups. Anchoring of the complex occurs through a post-synthetic exchange of formiate anions, coordinated at the zirconium clusters of the MOF, with the free carboxylate group of the [Ir(HEDTA)Cl]-complex. The modified material was tested as heterogenous catalyst for the WO reaction by using Cerium Ammonium Nitrate as sacrificial agent. Although TOF and TON values are comparable to those of other iridium heterogenized catalysts, the MOF exhibits iridium leaching not limited at the first catalytic run, as usually observed, suggesting a lack of stability of the hybrid system under strong oxidative conditions.

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A Highly Active and Easily Accessible Cobalt Catalyst for Selective Hydrogenation of C═O Bonds

Journal of the American Chemical Society ◽

10.1021/jacs.5b04349 ◽

2015 ◽

Vol 137 (25) ◽

pp. 7998-8001 ◽

Cited By ~ 146

Author(s):

Sina Rösler ◽

Johannes Obenauf ◽

Rhett Kempe

Keyword(s):

Selective Hydrogenation ◽

Cobalt Catalyst ◽

Highly Active

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