Influence of Perfluorinated End Groups on the SFRD of [Pt(cod)Me(C_nF_2n+1)] onto Porous Al₂O₃ in CO₂ under Reductive Conditions

Abstract

The optimized synthesis of a range of cyclooctadiene-stabilized Pt complexes that contained different perfluoro-alkane chains, [Pt(cod)Me(Cn F2n+1 )], is presented. These metal-organic compounds were employed in the so-called supercritical fluid reactive deposition (SFRD) in CO2 under reductive conditions to generate metallic nanoparticles on aluminum oxide as a porous support. Thus, Al2 O3 -supported Pt nanoparticles with a narrow particle-size distribution were obtained. At a reduction pressure of 15.5 MPa and a temperature of 353 K, particle diameters of d50 =2.3-2.8 nm were generated. Decreasing the pressure during the reduction reaction led to slightly larger particles whilst decreasing the amount of organometallic precursor in CO2 yielded a decrease in the particle size from x50 =3.2 nm to 2.6 nm and a particle-size distribution of 2.2 nm. Furthermore, substitution of the CH3 end group by the Cn F2n+1 end groups led to a significant drop in Pt loading of about 50 %. Within the series of perfluorinated end groups that were considered, the Pt complex that contained a branched perfluoro-isopropyl group showed the most-interesting results when compared to the control precursor, [Pt(cod)Me2 ] (1).

Metal complexes as a promising source for new antibiotics

“…for metal organic vapor deposition (MOCVD) or supercritical uid reactive deposition (SFRD) for the manufacture of optoelectronics or catalysts. 47,48 In addition to structures to 17 and 18, seven similar structures showed selective activity against the two fungal strains tested. Previously reported compounds of this class showed elevated toxicity against HeLa cells.…”

Origin of the Normal and Inverse Hysteresis Behavior during CO Oxidation over Pt/Al2O3

“…Finally, the system was slowly depressurized and cooled to ambient conditions. More details can be found in the literature. − …”

Oxidation State and Dielectric Properties of Ceria-Based Catalysts by Complementary Microwave Cavity Perturbation and X-Ray Absorption Spectroscopy Measurements

“…The present study is intended to show the change in dielectric properties during exposure to reducing/oxidizing gas mixtures at different temperatures up to 550 °C by applying the cavity perturbation method. In addition to CeO 2 , 1 wt% Pt/CeO 2 samples prepared by single or two nozzles flame spray pyrolysis (FSP/TFSP) [33] and supercritical fluid reactive deposition with carbon dioxide (SFRD) [34][35][36][37] were tested. To confirm the correlation between the resulting oxidation state of ceria and the observed dielectric properties, complementary in situ XAS measurements at the Ce L 3 -edge were performed during gas atmosphere variation.…”