京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22457号 / 工博第4718号 / 新制||工||1737(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 大江 浩一, 教授 中村 正治, 教授 中尾 佳亮 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

abstract: This study reports on the treatment of ammunition wastewater containing RDX (1,3,5-Trinitro-1,3,5-triazinane), HMX (1,3,5,7-Tetranitro-1,3,5,7-tetrazoctane), and the oxyanion co-contaminants nitrate (NO3-) and perchlorate (ClO4-) in a membrane biofilm reactor (MBfR), a Palladium (Pd)-coated MBfR (Pd-MBfR), and an abiotic Pd-coated film reactor (Pd-film reactor). A consortium of nitrate- and perchlorate-reducing bacteria, continuously fed with synesthetic ammunition wastewater featuring 4 mM nitrate and 0.1-2 mM perchlorate, formed robust biofilms on the membrane surfaces in the MBfR and Pd-MBfR. PdNPs with diameter 4-5-nm auto-assembled and stabilized on the surfaces of membrane and biofilm in MPfR and Pd-MBfR. Nitrate and perchlorate were rapidly reduced by the biofilms in the MBfR and Pd-MBfR, but they were not catalytically reduced through PdNPs alone in the MPfR. In contrast, RDX or HMX was recalcitrant to enzymatic degradation in MBfR, but was rapidly reduced through Pd-catalytic denitration in the MPfR and Pd-MBfR to form ‒N‒NHOH or ‒N‒H. Based on the experimental results, the synergistic coupling of Pd-based catalysis and microbial activity in the Pd-MBfR should be a viable new technology for treating ammunition wastewater. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2019

>Magister Scientiae - MSc / Due to the negative impact on the environment and the associated biological risks on human and animal life, the need for eco-friendly synthetic protocols is critical. With the rapid advancement in nanotechnology, this extends to the synthesis of nanomaterials. Eco-friendly nanoparticle synthesis protocols have led to the use of fungi, plants and other biological substances, due to their remarkable ability in reducing metal ions. This led to the formation of very efficient hybrid catalysts, which are partially organic/inorganic composites. Palladium nanoparticles have drawn much interest due to its potential in catalytic applications and in photovoltaic cell development. In this study, the brown marine algae, Ecklonia radiata, was employed as a putative palladium nanoparticle bioreactor. Aqueous extracts of the algae were used as a supporting matrix for the synthesis of palladium nanoparticle (AE-PdNPs) catalysts according to the principles of green chemistry. The catalysts were then assessed for their capability in various carbon-carbon coupling reactions such as Suzuki-Miyaura, Sonogashira, and Heck coupling reactions. Selectivity studies were also performed. The PdNPs were compared to “model” polyvinylpyrrolidone palladium nanoparticles (PVP-PdNPs), synthesized according to literature methods. A variety of spectroscopic techniques were used to characterize the nanoparticles and the organic reaction products, including HRTEM, EDX, NMR, FTIR, DLS, TGA, UV-Vis, ICP-AES, GC-MS and XRD spectroscopy. qNMR was used to determine the product % yields. The aqueous extracts were characterised using NMR and a variety of assays, including total antioxidant potential, total reducing power and radical scavenging ability) to assess its ability to reduce the Pd metal salt. 2D NMR revealed polysaccharides and polyphenols to be the major and minor components, respectively, present in the extract. HRTEM images revealed the average size of the AE-PdNPs and PVP-PdNPs to be 12 nm and 8 nm, respectively. The images also showed the shapes of the NPs to be cubic for the AE-PdNPs and cubic or triangular for the PVP-PdNPs. SAED and XRD spectroscopy revealed the face-centred cubic phase and polycrystalline nature of the AE-PdNPs. No reliable data, other than the HRTEM images was obtained for the PVP-PdNPs. Zeta potential and DLS measurements confirmed the negative charge present on the surface of the nanoparticles, while the hydrodynamic radii were found to be 65 nm and 99 nm for the AE- and PVP-PdNPs, respectively, substantiating the presence of the capping agents. ICP-AES analysis revealed the Pd content of the NPs to be 48.8 and 28.9 ppm for the AE- and PVP-PdNPs. Following characterization, the PdNPs were assessed as potential catalysts in the Suzuki-Miyaura, Heck and Sonogashira carbon-carbon coupling reactions. Bromo and iodo substrates were employed, together with sterically hindered substrates, with a nitro moiety in the ortho or para positions. For the Suzuki-Miyaura reactions, both sets of PdNPs revealed slightly higher yields for the products synthesized using the bromo substrate (>90%), while low yields (40 – 55% yields) were obtained for the ortho substituted substrate in comparison to the para substrate (>90% yields). The Heck coupling reactions with butyl acrylate and 4-iodoacetphenone were successful (~70% yields), while reactions with 4-bromoacetophenone failed. However, the Sonogashira couplings did not proceed at all. With the series of reactions NPs showed some selectivity, with the AE-PdNPs consistently producing higher yields for the products obtained. This may be due to overall nature of the NPs, or due to the higher platinum loading content for the AE-PdNPs.

Thesis advisor: James P. Morken / This dissertation describes the development of various palladium-catalyzed syntheses of organoboron compounds with the 1,2-metallate shift of organoboron “ate” complexes as a common mechanistic feature. Chapter one discusses the history of the 1,2-metallate shift with a focus on reactions promoted by transition metals, followed by my work on the palladium-catalyzed, enantioselective, halide-tolerant conjunctive cross-coupling reaction to enable the use of Grignard reagents and arylbromides. Chapter two discusses the attempt to engage allylic electrophiles in the conjunctive cross-coupling reaction and the discovery and optimization of the vinylidenation reaction to access 1,1-disubstituted boryl alkenes. Unlike other palladium-catalyzed reactions that proceed by a 1,2-metallate shift, the vinylidenation proceeds by a β-hydride elimination rather than a reductive elimination as the final step in the catalytic cycle. Chapter three discusses the development of the enantioselective conjunctive cross-coupling of propargylic electrophiles to access enantioenriched β-boryl allenes. Methanol additive was found to improve both the yield and enantioselectivity of the reaction. 1H NMR studies show that methanol exchanges with the pinacol ligand on the boron “ate” complex. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Bifunctional catalysts consisting of palladium or platinum and supported on amorphous silica-alumina were prepared and tested in the hydrocracking of n-hexadecane, which is considered to be representative of n-paraffins in hydrocracker feeds. In addition to the evaluation of the  physicochemical properties, a comprehensive study on catalyst activity and selectivity has been conducted, in the full range of conversions. A theoretical model was proposed to fit the experimental conversion-selectivity data. The n-hexadecane reactivity pattern was expressed in terms of a reaction network involving lumps consisting of monobranched and multibranched n-hexadecane isomers, and cracking products. Pseudo first order kinetics and irreversible reaction steps were assumed in order to obtain the kinetic constants of each step. For the same metallic molar loading, a platinum-based catalyst proved more active than a palladium one. The reaction network model showed that cracking products were produced by means of a bifunctional mechanism on palladium catalysts, with n-hexadecane isomers as intermediates. However, on platinum catalysts, an additional monofunctional mechanism was observed. The noble metal catalyzes the hydrogenolysis of n-hexadecane without requiring any acid function. An increase in the platinum loading leads to an increase in the importance of this direct cracking route. The deactivation in the platinum-based catalysts is only due to coke formation, which deactivates the metal sites. The regeneration by means of a Temperature-Programmed Oxidation does not lead to a complete recovery of the metal function, according to the volumetric chemisorption measurements and the experimental selectivity  data. Further work is required to determine the real causes.

Fischer-Tropsch synthesis enables the production of high quality diesel fuel from biomass derived synthesis gas. In order to increase the overall diesel yield, it is necessary to perform a subsequent hydrocracking of the long-chain linear paraffins. This work is focused on characterization and testing of catalysts for the hydrocracking reaction of Fischer-Tropsch waxes. In particular, noble metal catalyst based on Pt and Pd on amorphous silica-alumina support were tested. Palladium based catalysts performed nearly an ideal bifunctional mechanism, while platinum based catalysts performed another way of cracking: hydrogenolysis. Platinum based catalysts are more active than palladium ones, with the same metal loading. This is a consequence of the nature of the metal sites. The product distribution is similar for both platinum and palladium catalysts. However, due to the hydrogenolysis cracking mechanism performed by platinum based catalysts, the amount of light gases produced on platinum based catalysts is higher. Furthermore, the deactivation behavior of the Platinum and Palladium catalysts has been studied, and the results showed that the dispersion of the active phase decreased with deactivation and the average crystallite diameter increased. This means a decrease in activity. A regeneration program, temperature programmed oxidation (TPO), has been carried out demonstrating that the activity was not completely recovered.

Se ha estudiado la actividad catalítica de materiales derivados de grafeno como soporte de nanopartículas de paladio así como de complejos de paladio(II) en reacciones de acoplamiento carbono-carbono y carbono-heteroátomo. Así mismo, se ha llevado a cabo su actividad catalítica como carbocatalizador en diversas transformaciones orgánicas.

The tetraphosphine DPPEPM reacts with [PtMe2(cod)] to produce [PtMe2(DPPEPM-PP)] (1) in near quantitative yield. On standing in solution, the free P atoms become oxidized to give [PtMe2(DPPEPM(O) 2-PP)] (1a), which has been characterized by X-ray crystallography. In contrast, reactions of DPPEPM with [MCl2(cod)] (M = Pd, Pt) yield ionic products of the form [M(DPPEPM-PP)2]MCl4 (3, 4). When a solution of the platinum complex was allowed to stand, crystals of [Pt(μ-Cl)(μ-DPPEPM)2]Cl3 (5) were obtained. In a third set of reactions, treatment of [PtClR(cod)] (R = Me, Ph) or [PdClMe(cod)] with DPPEPM gives species of the type [MR(DPPEPM-PPP)]Cl (6-8), in which one of the internal P atoms is uncoordinated. Reactions of [PtR2(DPPEPM-PP)] with [PtR2′(cod)] or [MCl2(cod)] (M = Pd, Pt), or of [PtR(DPPEPM-PPP)]Cl with [MCl2(cod)], lead to unsymmetrical bimetallic complexes. [PtMe2(μ-DPPEPM)PdCl2] (11) and [PtClPh(μ-DPPEPM)PdCl2] (14) have been characterized crystallographically. Trimetallic complexes of the form [{PtR 2(μ-DPPEPM)}2M][MCl4] (M = Pd, Pt, 15-17) are produced by reaction of [PtR2(DPPEPM-PP)] with [MCl 2(cod)].

The purpose of this study was to prepare and characterize complexes produced by the reactions of spermine and spermidine with palladium(II) chloride. A first analysis of the problem seemed to indicate that preparation of the complexes should be straightforward and not difficult. Bonding of the nitrogen atoms to the metals allows sterically for formation of two six-membered rings separated by a tetramethylene chain in a spermine complex, and by a six-membered chelate ring in a spermidine complex.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18301号 / 工博第3893号 / 新制||工||1597(附属図書館) / 31159 / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 村上 正浩, 教授 杉野目 道紀, 教授 大江 浩一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM