Browsing by Author "Finke, Richard G., advisor"
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Item Open Access Distinguishing homogeneous and heterogeneous water oxidation catalysis when beginning with cobalt polyoxometalates(Colorado State University. Libraries, 2013) Stracke, Jordan J., author; Finke, Richard G., advisor; Chen, Eugene Y.-X., committee member; Elliott, C. Michael, committee member; Ferreira, Eric M., committee member; Sites, James R., committee memberDevelopment of energy storage technologies is required prior to broad implementation of renewable energy sources such as wind or solar power. One of the leading proposals is to store this energy by splitting water into hydrogen and oxygen--that is, to store energy in chemical bonds. A major obstacle en route to this overall goal is the development of efficient, cost-effective water oxidation catalysts (WOCs). Due to the highly oxidizing environment needed to drive this reaction, one question which has arisen when dealing with homogeneous precatalysts is whether these precursors remain as intact, homogeneous WOCs, or whether they are transformed into heterogeneous metal-oxide catalysts. This problem, reviewed in Chapter II, addresses the methods and literature studies related to distinguishing homogeneous and heterogeneous water oxidation catalysts. Chapters III through V further develop the methodology for distinguishing homogeneous and heterogeneous water oxidation catalysis when beginning with the cobalt polyoxometalate [Co4(H2O)2(PW9O34)2]10- (Co4POM). In Chapter III, the investigation of Co4POM using electrochemical oxidation at a glassy carbon electrode reveals that under the conditions therein, an in-situ formed, heterogeneous cobalt-oxo-hydroxo (CoOx) material is the dominant catalyst and is formed from Co2+ leached from the Co4POM. In Chapter IV, investigation of whether the intact Co4POM could be a catalyst under other, more forcing conditions of higher electrochemical potentials and lower Co4POM concentrations is reported. Although the Co4POM shows different electrochemical properties relative to CoOx controls, the possibility that the Co4POM is being transformed into a meta-stable heterogeneous catalyst cannot be ruled out since the Co4POM degrades during the experiment. Lastly, Chapter V presents a kinetic and mechanistic study of the Co4POM when using a ruthenium(III)tris(2,2'-bipyridine) (Ru(III)(bpy)33+) chemical oxidant to drive the water oxidation reaction (i.e., rather than electrochemically driven oxidation). In this study, it was found that Co4POM catalyzes the oxidation of water as well as oxidation of the 2,2'-bipyridine ligand. In contrast, controls with in-situ formed CoOx catalysts more selectively promote the catalytic oxidation of water. The difference in reactivity and kinetics between the Co4POM and CoOx systems indicates that the active catalysts are fundamentally different when a chemical oxidant is employed. Overall, these studies demonstrate the need for careful experimental controls and highlight the importance which reaction conditions--in particular the source and electrochemical potential of the oxidant--can play in determining the active oxidation catalyst in water oxidation reactions.Item Open Access Investigations of the identity of the true catalyst in three systems, including the development of catalyst poisoning methodology(Colorado State University. Libraries, 2012) Bayram, Ercan, author; Finke, Richard G., advisor; Chen, Eugene Y.-X., committee member; Prieto, Amy L., committee member; Bernstein, Elliot R., committee member; Dandy, David S., committee memberFollowing brief reviews of the pertinent "who is the catalyst?" and "M4 (M= transition-metal) cluster catalysis" literature, the research presented herein is focused on the investigations of the true catalyst for three different catalytic systems. The studies include: (i) the investigation of the true catalyst for neat benzene hydrogenation beginning with commercially available [Ir(cod)Cl]2 (cod= 1,5-cyclooctadiene) at 22 °C and 40 psig initial H2 pressure; (ii) the investigation of the true catalyst for benzene hydrogenation beginning with commercially available [RhCp*Cl2]2 (Cp*= pentamethylcyclopentadienyl) at 100 °C and 50 atm (740 psig) initial H2 pressure; and (iii) the investigation of the true catalyst for cyclohexene hydrogenation beginning with the well-characterized, site isolated [Ir(C2H4)2]/zeolite-Y complex at 22 °C and 40 psig initial H2 pressure, studies done collaboratively with Professor Bruce C. Gates and his group at the University of California-Davis. All three investigations aimed at identifying the true catalyst were studied via an arsenal of complimentary techniques including kinetics, in operando and post-catalysis X-ray absorption fine structure (XAFS) spectroscopy, kinetic quantitative poisoning experiments, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and high-angle annular dark-field scanning electron microscopy (HAADF-STEM). The data obtained for each system presented herein provide compelling evidence that the proposed species in each chapter are the true catalyst of the given system, specifically (and respectively) for (i), (ii), and (iii) above Ir(0)n nanoparticles and aggregates, Rh4 sub-nanometer clusters, and atomically dispersed, mononuclear Ir1/zeolite Y catalysts. The results emphasize the need to use complimentary, multiple methods in order to correctly identify the true catalyst in such catalytic systems. The final study elucidates kinetic quantitative catalyst poisoning via two model catalysts: Rh(0)n nanoparticles and Rh4 clusters, providing detailed analyses of linear as well as non-linear kinetic quantitative poisoning plots. The resulting quantitative kinetic catalyst poisoning studies of Rh(0)n nanoparticles and Rh4 clusters led to estimates of the equivalents of poison bound, quantitative catalyst poisoning association constants, and the numbers of active sites for each catalyst.Item Open Access Kinetic and mechanistic studies of supported-nanoparticle heterogeneous catalyst formation in contact with solution(Colorado State University. Libraries, 2011) Mondloch, Joseph E., author; Finke, Richard G., advisor; Bailey, Travis S., committee member; Ferreira, Eric M., committee member; Prieto, Amy L., committee member; Shores, Matthew P., committee memberThis dissertation begins with a comprehensive and critical review of the literature addressing the kinetics and mechanism(s) of supported-nanoparticle heterogeneous catalyst formation. The review chapter that follows makes apparent that routine kinetic monitoring methods, as well as well-defined supported-nanoparticle formation systems, are needed in order to gain fundamental insights into the mechanisms of supported-nanoparticle heterogeneous catalyst formation--a somewhat surprising finding given the long history as well as commercial importance of heterogeneous catalysis. Hence, the research presented within this dissertation is focused on (i) developing a kinetic monitoring method (i.e., in what follows, the cyclohexene reporter reaction method) capable of measuring supported-nanoparticle formation in contact with solution, and (ii) developing a well-defined supported-nanoparticle formation system, also in contact with solution, that is amenable to rigorous mechanistic studies. Development of the cyclohexene reporter reaction has allowed for the rapid and quantitative monitoring of the kinetics of Pt(0)n/Al2O3 and Pt(0)n/TiO2 supported-nanoparticle heterogeneous catalyst formation in contact with solution from H2PtCl6/Al2O3 and H2PtCl6/TiO2 respectively. Importantly, those kinetic studies revealed conditions where the most desirable, chemical-reaction-based, supported-nanoparticle formation conditions are present rather than diffusional-limited kinetic regimes. The largest drawback when utilizing the H2PtCl6 as a supported-precatalyst is its speciation--that is, other solvated Pt-based species form when in contact with solution. Such non-uniform speciation leads to a large variation in the supported-nanoparticle formation kinetics, observations that were obtained through the use of the cyclohexene reporter reaction kinetic monitoring method. Due to the large variability in the formation kinetics associated with the H2PtCl6 precatalyst speciation, synthesized next as a part of this dissertation work was the well-defined, fully characterized, speciation-controlled supported-organometallic precatalyst, Ir(1,5-COD)Cl/γ;-Al2O3. When in contact with acetone, cyclohexene and H2 this supported-precatalyst was found to evolve into a highly active and long-lived Ir(0)~900/γ;-Al2O3 supported-nanoparticle catalyst. The kinetics of Ir(0)~900/γ-Al2O3 formation were successfully followed by the cyclohexene reporter reaction method and found to be well-fit by a two-step mechanism consisting of nucleation (A → B, rate constant k1) followed by autocatalytic surface growth (A + B → 2B, rate constant k2) previously elucidated by Finke and Watzky. More specifically, nucleation was found to occur in solution from Ir(1,5-COD)Cl(solvent), while nanoparticle growth occurs on the γ-Al2O3 support, but in a reaction that involves the Ir(1,5-COD)Cl(solvent) species in solution. Most importantly, the fits to the two-step mechanism suggest that the nine synthetic and mechanistic insights, of nanoparticle formation in solution, should now be applicable to the formation of supported-nanoparticle heterogeneous catalysts in contact with solution. That is, it seems reasonable to expect that these studies will allow a more direct avenue for transferring both the mechanistic and synthetic insights that have resulted from the modern revolution in nanoparticle science to the synthesis of size, shape and compositionally controlled supported-nanoparticle catalysts under the nontraditional, mild and flexible conditions where supported organometallics and other precursors are in contact with solution.Item Open Access Mechanistic studies of nanocluster nucleation, growth, and agglomeration(Colorado State University. Libraries, 2009) Finney, Eric E., author; Finke, Richard G., advisorFollowing a critical review of the relevant literature, the research presented herein focuses on the mechanisms by which transition-metal nanoclusters nucleate, grow, and agglomerate. The studies include: (i) the generality of the recently uncovered, 4-step mechanism for nanocluster formation and agglomeration; (ii) a study addressing the question of whether the hydrogenation of olefins using (1,5-COD)PtII complexes proceeds via homogeneous or heterogeneous catalysis; and (iii) a comparison of the kinetics of transition-metal nanocluster formation and the kinetics of solid-state reactions. Recently, a new, 4-step mechanism was discovered for the nucleation, growth, and agglomeration of transition-metal nanoclusters, using a single Pt complex in the system under study. Herein, the mechanism is shown to be general to the formation of nanoclusters of at least four other metals. In addition, the effects of ligands, concentration, temperature, solvent, and stirring on the mechanism are examined. Several alternative mechanisms are ruled out, leaving the 4-step mechanism as the only one to date that can account for the observed kinetics. The question of "is it homogeneous or heterogeneous catalysis?" is addressed with respect to the hydrogenation of olefins using (1,5-COD)Pt II complexes. The data presented herein provide compelling evidence that these complexes are first reduced to Pt0 nanoclusters and/or bulk metal, which are the true hydrogenation catalysts. Included herein is a brief overview of the literature of Pt-catalyzed hydrosilylation reaction, with respect to the "is it homogeneous or heterogeneous catalysis?" question. The literature is replete with mechanisms describing solid-state phase transitions, the kinetics of which appear similar to the kinetics of transition-metal nanocluster formation. It is found that the solid-state equation can fit nanocluster formation kinetic data, and vice versa. This finding leads into a comparison of solid-state reaction mechanisms and the Finke-Watzky mechanism, with a focus on the strengths and limitations of each.Item Open Access Part I. Fitting protein aggregation kinetic data relevant to neurodegenerative diseases with an "Ockham's Razor" model en route to meaningful rate constants and mechanistic insights. Part II. Dioxygenases: the development of new, and the reinvestigation of prior, precatalysts(Colorado State University. Libraries, 2009) Morris, Aimee M., author; Finke, Richard G., advisorThis dissertation is presented in two parts. Part I starts with a review of models that have been used to curve-fit or obtain rate constants for protein aggregation kinetic data. Following the review, the research presented in Part I is primarily focused on fitting protein aggregation literature relevant to neurodegenerative diseases using the Finke-Watzky (hereafter F-W) 2-step model of nucleation and autocatalytic growth. Part I includes: (i) the fits to the F-W model and resultant nucleation and growth rate constants of 14 representative data sets of amyloid-β, α-synuclein, and polyglutamine aggregation relevant to Alzheimer's, Parkinson's, and Huntington's diseases, respectively; (ii) the fits of 27 data sets of yeast and mammalian prion aggregation, along with the resultant rate constants and interpretation of factors that contribute to nucleation and growth of prion aggregates; and (iii) a re-examination of variable temperature and variable pH α-synuclein aggregation data in which the insights are elucidated that: (a) the processes of nucleation and growth are energetically similar, (b) the net charge of the protein affects nucleation, and (c) the lag-time does not, as previously thought, correspond to the rate of nucleation. Part II begins with a brief review of the importance of dioxygenases followed by an introduction to two important synthetic dioxygenases, the catechol dioxygenase [VO(3,5-DTBC)(3,5-DBSQ)]2 (where 3,5-DTBC = 3,5-di- tert-butylcatechol and 3,5-DBSQ = 3,5-di-tert-butylsemiquinone) and the claimed polyoxometalate dioxygenase, [WZnRu2(OH)(H 2O)(ZnW9O34)2]11-. The synthesis and characterization of a new dioxygenase, V(3,6-DBSQ)(3,6-DTBC) 2, along with the initial catalytic results with the H2(3,6-DTBC), substrate are given. Next is a full report of the dioxygenase activity with H2(3,5-DTBC) and H2(3,6-DTBC) substrates of three d 0 metal precatalysts: [VO(3,5-DTBC)(3,5-DBSQ)]2, V(3,6-DTBC) 2(3,6-DBSQ), and [MoO(3,5-DTBC)2]2. The d 0 vanadium bound to a semiquinone ligand in both V-precatalysts appears to be an important component for obtaining dioxygenase products from the H 2(3,5-DTBC) and H2(3,6-DTBC) substrates. Finally, Part II concludes with a reinvestigation a claimed dioxygenase, [WZnRu2(OH)(H 2O)(ZnW9O34)2]12- (1). Three independent samples of 1 from two different laboratories, samples that also give the same catalysis results as previously reported, are all consistent with the composition of the parent, Ru-free polyoxometalate, [WZn3(H2O)2(ZnW9O34) 2]12- (2). Also, simple mixtures of 2 plus [Ru(DMSO)4Cl2] is a ca. 2-fold more efficient catalyst than "1", placing in serious doubt a prior Nature paper detailing the claim that "1" is a Ru-based, all-inorganic dioxygenase.Item Open Access Photoelectrochemical cells employing molecular light-harvesting materials for the capture and conversion of solar energy(Colorado State University. Libraries, 2017) Kirner, Joel Thomas, author; Finke, Richard G., advisor; Reynolds, Melissa, committee member; Van Orden, Alan, committee member; Sampath, Walajabad, committee memberSolar light has the potential to be a substantial contributor to global renewable energy production. The diffuse nature of solar energy requires that commercially viable devices used to capture, convert, and store that energy be inexpensive relative to other energy-producing technologies. Towards this end, photoelectrochemical cells have been the subject of study for several decades. Particularly interesting to chemists, molecular light-harvesting materials can be employed in photoelectrochemical cells. For example, a dye-sensitized solar cell (DSSC) is a type of photoelectrochemical cell designed to capture solar energy and convert it to electricity. Alternatively, molecular light-harvesting materials have also been employed in water-splitting photoelectrolysis cells (PECs), which capture solar energy and store it in the form of chemical bonds such as H2 and O2. The work presented in this dissertation falls into two major projects. The first involves fundamental studies of water-oxidizing PECs employing a novel perylene diimide molecule as the light-harvesting unit. Background is provided in Chapter II, composed of a comprehensive literature review of water-oxidizing PEC systems that employ light-harvesting materials composed of earth-abundant elements. Chapter III describes preliminary studies of a water oxidizing PEC composed of a perylene diimide organic thin-film (OTF) and cobalt oxide catalyst, the first of its kind in the literature. Characterization of this novel device provided knowledge of the efficiency-limiting processes that would need to be addressed in order to improve device performance. Subsequently, Chapter IV describes preliminary studies of the same perylene diimide molecule in an alternative, literature-precedented, dye-sensitized photoelectrolysis cell (DS-PEC) architecture aimed at improving the efficiency-limiting processes of the first OTF-PEC. Characterization of this DS-PEC architecture reveals that the efficiency-limiting processes of the OTF-PEC were indeed improved. However, deposition of the cobalt oxide catalyst onto the DS-PEC did not successfully result in water oxidation. Alternative catalyst-deposition strategies from the literature are described as direction for future studies. The second project of this dissertation involves the study of novel high-redox-potential organometallic cobalt complexes as redox mediators in DSSCs, and is presented in Chapter V. Therein, it was found that the use of electron-withdrawing functional groups on cobalt coordinating ligands not only increased the redox potential, but also increased the lability of the ligands. The resulting complex instability caused performance-limiting electron-recombination reactions in assembled DSSCs. These results point future researchers towards the study of higher-chelating ligands for enhanced stability in high-potential cobalt complexes.Item Open Access Synthesis and characterization of iridium model, and cobalt and nickel, industrial Ziegler-type hydrogenation catalysts and their precursors(Colorado State University. Libraries, 2011) Alley, William Morgan, author; Finke, Richard G., advisor; Chen, Eugene Y.-X., committee member; Elliott, C. Michael, committee member; Levinger, Nancy E., committee member; Kipper, Matthew J., committee memberFollowing a comprehensive critical review of the pertinent literature, the research presented herein is focused on the synthesis of an Ir precursor used to model industrial Ziegler-type hydrogenation catalysts, and on catalyst characterization using both the Ir model, and genuine Co and Ni, industrial catalyst materials. The studies include: (i) the synthesis, characterization, and initial catalytic investigation of Ir (and Rh) compounds for use as models for the industrial Co and Ni Ziegler-type hydrogenation catalysts; (ii) characterization of the Ziegler-type hydrogenation catalyst made from the Ir precursor; and (iii) characterization of the authentic industrial Co and Ni Ziegler-type hydrogenation catalysts. The synthesis and definitive characterization of Ir (and Rh) precatalysts designed to facilitate investigation into the homogeneous versus heterogeneous nature of Ziegler-type hydrogenation catalysts is described herein. Additionally, the ability of these Ir (and Rh) precatalysts to form active Ziegler-type hydrogenation catalysts upon combination with AlEt3 is demonstrated. The homogeneous versus heterogeneous nature of the Ir Ziegler-type hydrogenation catalyst is investigated using several complementary analytical methods plus kinetic studies. Initial active catalyst solutions contain a variety of Ir species ranging from mono-Ir compounds to nanometer-scale Irn clusters, but on average are subnanometer, Ir~4-15 species. However, crystalline Ir(0)~40-150 nanoclusters are rapidly formed when the solutions are put under pressurized H2 gas, and these larger, "Ziegler nanoclusters" are shown to be the most active catalysts, an important result in comparison to all the prior, extensive literature of these important industrial catalysts. The homogeneous versus heterogeneous nature of the authentic industrial Co- and Ni-based Ziegler-type hydrogenation catalysts are investigated using an approach parallel to that used for the Ir system, and are compared to the results from the Ir model system. The metal cluster species are essentially the same pre- and posthydrogenation; they comprise a broad distribution of Mn cluster sizes from subnanometer to nanometer in scale, with average diameters of about one nanometer, and with some amount of unreduced mono-metallic complexes also present dependent on the Al/M ratio. These findings support the primary working hypothesis present in the most recent literature, namely that Ziegler-type hydrogenation catalysis is enacted by "Ziegler nanoclusters" (as defined herein), nanoclusters of size M4 in the case of the industrial Co and Ni system.Item Open Access Synthesis, characterization and catalytic evaluation of a Ziegler-type model iridium hydrogenation catalyst plus a novel tetrairidium tetrahydride complex(Colorado State University. Libraries, 2013) Hamdemir, Isil Kayiran, author; Finke, Richard G., advisor; Bernstein, Elliot R., committee member; Chen, Eugene Y.-X., committee member; Elliott, C. Michael, committee member; Wang, David, committee memberFollowing a critical review of the pertinent literature of Ziegler-type hydrogenation catalysts, the research presented herein is primarily focused on the synthesis, characterization and catalytic properties of a model Ziegler-type hydrogenation catalyst system made from [Ir(1,5-COD)(μ-O2C8H15)]2 plus AlEt3. The studies include: (i) a critical review of the relevant literature, (ii) ranking the activity, lifetime and thermal stability of the resulting Ir(0)n Ziegler nanoparticles; (iii) characterization of the true stabilizer species for Ir(0)n Ziegler nanoparticles as a function of the initial Al/Ir ratio; and (iv) the synthesis and characterization of a novel [Ir(1,5-COD)(μ-H)]4 complex considered as a plausible intermediate en route to Ir(0)n Ziegler nanoparticles. Studies evaluating and ranking the catalytic properties of Ziegler-type catalysts in the test reaction of cyclohexene hydrogenation reveal that the catalyst made with [Ir(1,5-COD)(μ-O2C8H15)]2 plus AlEt3 is a highly catalytically active, long-lived and thermally unusually stable nanoparticle catalyst. The catalytic lifetimes of the Ir(0)n Ziegler nanoparticles are higher than any known Ir(0)n nanoparticles in the extant literature. The nature of the stabilizer species in the Ziegler-type catalyst system made with [Ir(1,5-COD)(μ-O2C8H15)]2 plus AlEt3 at Al/Ir ratios 1-3 is then investigated by comparing 1H, 13C, 27Al NMR and IR data of the catalysts with those of individually-synthesized standards such as AlEt2(O2C8H15), [(n-Bu)4N][AlEt3(O2C8H15)] and [(n-Bu)2Al(µ-OH)]3. The results of the study shows that (i) AlEt2(O2C8H15) (Al/Ir=1, 2 and 3) and (iii) free AlEt3 (Al/Ir=3) are present in the catalyst solution in this model Ziegler-type hydrogenation catalyst system made from [Ir(1,5-COD)(μ-O2C8H15)]2 plus AlEt3. The spectroscopic and catalytic evidence provided in this study helps to rule out the initial hypotheses (iii) that anionic [AlEt3(O2C8H15)]- stabilizer exists and provides DLVO-type, Coulombic-repulsion stabilization. Also ruled out is (iv) that the AlEt3-derived stabilizers are Al-O-Al containing alumoxanes. In a separate study, a novel [Ir(1,5-COD)(μ-H)]4 complex is synthesized and characterized with the goal of (i) obtaining information on formation and stabilization mechanisms of Ziegler-type industrial hydrogenation model catalysts prepared from [Ir(1,5-COD)(μ-O2C8H15)]2 plus AlEt3; and with the goal of (ii) understanding the stabilization efficacies of various Al-based cocatalysts in the absence of any added carboxylate.Item Open Access Water oxidation catalysis beginning with cobalt polyoxometalates: determining the dominant catalyst under electrocatalytic conditions and investigation of the surface properties of Co3O4 nanoparticles(Colorado State University. Libraries, 2018) Folkman, Scott Jerald, author; Finke, Richard G., advisor; Neilson, James, committee member; Strauss, Steven, committee member; Sites, James, committee memberGeneration of hydrogen as a fuel is one of the most promising technologies for a renewable energy future. Electrocatalytic water splitting can take energy from virtually any power source and split water into oxygen and hydrogen, thereby creating a renewable feedstock of hydrogen. The efficiency of electrocatalytic water splitting is limited by the anodic half reaction, water oxidation. As such, there has been an immense effort to discover and understand water oxidation catalysts (WOCatalysts). The two main classes of WOCatalysts are homogeneous and heterogeneous catalysts. Homogeneous catalysts are typically soluble molecular complexes that have a single type of active site, allowing for rational tuning through synthesis, and mechanistic studies. Heterogeneous catalysts are typically in a different phase from the reaction (i.e. insoluble or electrode-bound) and have a spectrum of active sites that are more difficult to identify. This Dissertation examines a class of inorganic compounds called polyoxometalates (POMs), and investigates the nature of the kinetically dominant, homogeneous vs heterogeneous catalyst. Chapter I provides an in depth introduction to water oxidation catalysis and in particular with cobalt-based POMS. Chapters II and III focus on the polyoxometalate, [Co4(H2O)2(VW9O34)2]10− (hereafter Co4V2W18) which has been claimed to be one of the fastest WOCatalysts to date. Those studies demonstrate that Co4V2W18 is, in fact, very unstable and dissociates 87-100% of the Co(II) originally present in Co4V2W18 into solution within three hours when dissolved in 0.1 sodium phosphate buffer (NaPi) at pH 5.8 and 8.0 as well as sodium borate buffer (NaB) pH=9.0. The dissociated Co(II)aq then forms heterogeneous cobalt-oxide (CoOx) on a glassy carbon electrode under electrocatalytic WOCatalysis conditions. The deposited CoOx accounts for 100±15% of the observed catalysis current. This finding demonstrates that the original Co4V2W18 serves only as a precursor to heterogeneous CoOx which is the dominant WOCatalyst. Chapter IV details studies using a selection of the most stable and most active Co-POMs to date. These studies demonstrate that none of the Co-POMs examined are 100% stable, and they release between 0.6 and >90% of the cobalt in the original complex within three hours in 0.1 M NaPi pH=5.8 or 8.0 and NaB pH=9.0. Furthermore, in 13 of the 18 cases examined, heterogeneous CoOx forms on the glassy carbon electrode and accounts for ≥100% of the observed WOCatalysis current. Lastly, under conditions where the Co-POMs are stable (<2% decomposition), the evidence provided implies that some of the Co-POMs are homogeneous WOCatalyst. Other implications regarding the stability trends and nature of the true catalyst are provided. The last research chapter, Chapter V, consists of the study of Co3O4 nanoparticles, which have been shown to be active for WOCatalysis. In this chapter, the synthesis, and surface properties of Co3O4 nanoparticles are investigated. It is demonstrated that ethanol/water (EtOH/water) as solvent forms phase-pure Co3O4 nanoparticles but following the same procedure in water yields a mixture of products. Therefore, EtOH must affect the product either thermodynamically (i.e. through a covalent EtO-Co linkage on the surface) or kinetically (i.e., by affecting the nucleation and/or growth of the particles). However, EtOH is not observed in the product; instead, acetate from the cobalt acetate precursor is the only detectable surface ligand. This implies that EtOH does not affect the thermodynamics of the particle formation, instead it must be involved in the kinetics of nucleation and/or growth of the Co3O4 nanoparticles. Through careful examination of the particle size and surface ligand data were able to obtain an average molecular formula of {[Co3O4(C2H3O2)−][(NH4+)0.3(H+0.7)]+·(H2O)}∼216 for the nanoparticles that we isolated. This chapter also includes general implications for the synthesis of metal-oxide nanoparticles in alcohol, and methods for identifying surface ligands.