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Although Pd-Au high-surface area catalysts are used in industry to improve activity and selectivity, a thorough understanding of the nature of these enhancements is lacking. A molecular-level understanding of catalytic reactions under actual reaction conditions is the ultimate goal. This thesis is mainly focused on the application of Pd-Au supported catalysts for vinyl acetate synthesis and CO oxidation reactions using highsurface area catalysts. We have attempted to improve the conventional Pd-Au based catalyst by synthesizing novel acetate-based and polymer-based catalysts. The corresponding catalytic reactivity and selectivity were measured and compared to conventional Pd-Au based catalyst systems. Subsequent characterization was performed using characterization techniques, such as, X-ray diffraction (XRD) and transmission electron microscopy (TEM). From our bimetallic catalytic studies, it was evident that the addition of Au to Pd leads to increased reactivity and selectivity. This surface modification is an important factor in the altered reaction kinetics for vinyl acetate (VA) synthesis and CO oxidation reactions. Promoted and unpromoted Pd-Au/SiO2/K+ catalyst were used for VA synthesis and the effect of pre-adsorbed O2, acetic acid and the role of oxygen were explored. The VA reaction rate of novel acetate-based Pd-Au/SiO2 catalyst was 3.5 times higher than conventional Pd-Au catalysts. Also, 100% selectivity was obtained for acetate-based Pd-Au/SiO2 at 130 oC and the VA formation rate was comparable to that of conventional Pd-Au catalysts. Therefore, the acetate-based Pd-Au/SiO2 catalyst seems very promising and can be explored further. Also, Pd(1):Au(4)/SiO2 catalysts demonstrate 100% CO conversion at much lower temperatures (90 oC) compared with other Pd-Au based catalysts. Furthermore, we were successful in obtaining sufficient CO oxidation activity with increased metal loading (5 wt%) and these catalysts did not deactivate under above-ambient reaction temperature conditions, which make 1:4 Pd- Au/SiO2 catalyst a good candidate for further exploration in CO oxidation reactions.

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ix, 219 leaves : photos., tables, graphs ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide. Dept. of Chemical Engineering, 1979

Reprints of 4 papers published by the author included in back of book / 181 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Physical and Inorganic Chemistry, University of Adelaide, 1974

<p> The radioactive 26Al is an important probe for the interstellar medium of our galaxy since it is observed through the emission of 1.8 MeV gamma rays from the decay of 26gAl produced by the proton capture on 25Mg. But the production of the galactic 26Al is now still not well determined partially due to the lack of knowledge of the important states in 26Si which dominate the large uncertainty in the 25 Al(p,γ)26Si reaction rate at nova temperatures.</p> <p> In nova explosions, the proton capture of 25Al competes with its β decay and bypasses the production of 26gAl, since the capture product 26Si decays quickly to 26mAl instead of its ground state, without the emission of the 1.8 MeV gamma ray. But at even higher temperatures, such as in supernova explosions, 26mAl can be excited to the higher excited states by thermal excitation and then quickly de-excite to the ground state, thereby enhancing the production of 26gAl. The energy levels in 26Si in the Gamow window corresponding to these temperatures therefore need to be well understood in order to determine the 25Al(p,γ)26Si reaction rate, and thus the production rate of 26Al in these explosive environments.</p> <p> Two experiments were performed to study the important states in 26Si : one is the p(27Si,d)26Si* reaction at the NSCL, aiming to construct the level scheme of low lying states around the proton threshold; the other experiment is a measurement of the elastic scattering of 25Al+p with CRIB at RIKEN in order to obtain information on states in a broad range above the proton threshold. Details of these two experiments and their data analyses will be presented in this thesis.</p> / Thesis / Doctor of Philosophy (PhD)

Pharmaceuticals and personal care products (PPCPs) are widely used, resulting in trace amounts being detected in the aquatic environment. This presence is of human health and ecological concern and it is necessary to determine the best methods to eliminate them from our waters. The oxidation of PPCPs by permanganate was evaluated using a spectrophotometer to monitor permanganate reduction. Thirty-nine compounds were chosen to represent numerous classifications, including beta blockers, cephalosporins, fluoroquinolones, macrolides, non-steroidal anti-inflammatory drugs, phenol structures, polypeptides, sulfonamides, tetracyclines, and triazines. The reactivity of each compound was determined by measuring the absorbance of permanganate over time as it reacted with an excess of the compound. The absorbance data was fit to a pseudo-first-order reaction model that accounted for the growth of manganese dioxide colloids. The most reactive groups that reduced permanganate within minutes at pH 7.0 were the cephalosporins, phenol structures, and tetracyclines. The majority of the remaining pharmaceuticals and personal care products were moderately or weakly reactive (reducing permanganate within hours). Caffeine, carbadox, monensin, simetone, and tri(2-carboxyethyl)phosphine were poorly reactive (reducing permanganate over days). Metoprolol was the only selected compound that was determined to be potentially non-reactive (no reaction after 1 day). Polarizability and refractive index of the organic compounds showed significant positive correlations (R-squared > 0.50) with the first-order reaction rates for non-steroidal anti-inflammatory drugs and the phenol structures group. The half-life of each PPCP was determined based on a typical dosage of permanganate used for pre-oxidation. Eleven of the thirty-nine PPCPs had a half-life of less than thirty minutes (a typical contact time), indicating that oxidation by permanganate may be a viable option. There are many opportunities for further research in this area, including investigating more PPCPs, physicochemical property correlations, and the impact of water quality conditions

The ubiquitous presence and chronic effect of pharmaceuticals is one of the emerging issues in environmental field. As a result of incomplete removal by sewage treatment plants, pharmaceuticals are released into the environment and drinking water sources. On the other hand, conventional drinking water treatment processes such as coagulation, filtration and sedimentation are reported to be ineffective at removing pharmaceuticals. Therefore, the potential presence of pharmaceuticals in finished drinking water poses a threat on public health. Antibiotics, as an important group of pharmaceuticals, are given special concerns because the potential development of bacteria-resistance. Ozonation and advanced oxidation processes are demonstrated to be quite effective at removing pharmaceuticals. The oxidation of pharmaceuticals is caused by ozone itself and hydroxyl radicals that are generated from ozone decomposition. Whether ozone or hydroxyl radicals are the primary oxidant depends on the specific pharmaceutical of interest and the background water matrix. In this research, erythromycin, a macrolide antibiotic, was chosen as the target compound because of its high detection frequency in the environment and its regulation status. The objective of this research was to investigate the removal performance of erythromycin by ozonation from the standpoint of kinetics. The effects of pH, carbonate and phosphate buffers, and initial ozone dose on ozonation of erythromycin were also studied. The second-order rate constant for the reaction between deprotonated erythromycin and ozone was determined to be 4.44x10⁹ M⁻¹·s⁻¹ while protonated erythromycin did not react with ozone. Ozone was determined to be the primary oxidant for erythromycin removal by ozonation. pH was found to have great positive impact on the degradation of erythromycin by ozonation due to the deprotonation of erythromycin at high pH. Carbonate and phosphate buffers were found to have negligible effects on the degradation of erythromycin by ozonation. Initial ozone dose showed a positive impact on the total erythromycin removal rate by ozonation. / text

Bibliography: leaves 168-174 / ix, 225 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Chemical Engineering, 1990

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22162号 / 工博第4666号 / 新制||工||1728(附属図書館) / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 宮原 稔, 教授 山本 量一, 教授 松坂 修二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM