Travel Grant: Aqueous Oxidation of Methanol by V-Containing Biocatalysts

鉴于相对于含V的酶，在无机负载的钒氧化物催化剂上甲醇氧化的相对先进的基本理解，目前存在将在钒氧化物无机催化剂的研究中开发的原位和操作方法应用于含钒生物无机酶催化剂的研究的极好的研究机会。 具体而言，就业的国家的最先进的时间分辨原位和operando光谱方法（拉曼，UV-vis，ATR-IR，51 V NMR和quick-XANES/EXAFS）在水溶液氧化反应过程中建立了基本的结构-活性关系的含钒酶的甲醇氧化。 这项研究计划的成功大大加强了与中东技术大学（土耳其安卡拉）的Onal教授研究小组的合作，该研究小组是密度泛函理论计算的领导者。与Onal教授的合作是由NSF支持的最近第六届东地中海化学工程会议的产物。本研究的目的是（1）建立有效的表征方法和途径，用于研究在水相中存在的HOOH和CH 3OH环境中的钒氧化物催化剂，并在毫秒到分钟的时间尺度上进行时间分辨原位和操作光谱研究（拉曼）采用先进的方法研究了氧化钒的结构、氧化态、反应中间体、反应机理、反应机理，和均相钒卤代过氧化物酶作为甲醇水相氧化的生物催化剂的动力学。如今，尖端的催化研究必须将相关反应条件下的最新分子光谱表征方法与最先进的密度泛函理论（DFT）相结合。水溶液中相当复杂的含V酶具有多个氧官能团（例如，末端V=O键、V-O-H键、桥接V-O-C键和过氧V-O2键），其振动归属在没有DFT计算的帮助下是不直接的。 建议与中东技术大学（土耳其安卡拉）的Onal教授小组合作对含V酶进行DFT计算，因为只有这样的研究才能提供对不同反应途径的反应能量学的分子水平的见解。只有将分子光谱学的见解与反应途径相结合，才能实现分子结构反应性关系，这是本研究计划的最终目标。建议的研究计划扩展了以前的气-固CH 3OH氧化催化研究的CH 3OH的液相氧化，也桥梁无机催化与水相生物无机催化的酶。时间分辨的原位和operando光谱方法的发展，调查无机和生物无机催化剂的水相催化显着先进的这项事业，并具有广泛的影响，许多水相催化应用。 钒酸盐生物无机酶可以提供一种“绿色”替代目前用于氧化反应中的传统无机催化剂，并且新的基本见解可以帮助开发改进的药物、治疗剂、糖尿病管理和生物催化工业应用。利哈伊组显着受益于暴露和培训的领先研究小组进行密度泛函理论计算。土耳其团队通过接触最先进的实验光谱催化剂表征方法以及理论与实验的结合而受益匪浅。

1057968WachsIn light of the relative advanced fundamental understanding of methanol oxidation over inorganic supported vanadium oxide catalysts relative to V-containing enzymes, there is currently an excellent research opportunity to apply the in situ and operando methodologies developed in the study of vanadium oxide inorganic catalysts to the study of vanadium containing bioinorganic enzyme catalysts. Specifically, the employment of state-of-the-art time resolved in situ and operando spectroscopic methods (Raman, UV-vis, ATR-IR, 51V NMR and quick-XANES/EXAFS) during aqueous oxidation reactions establish the fundamental structure-activity relationships for methanol oxidation by vanadium-containing enzymes. The success of this research program is greatly enhanced by collaboration with the research group of Professor Onal at Middle Eastern technical University (Ankara, Turkey), a leader in density functional theory calculations. The collaboration with Professor Onal is an outgrowth of the recent 6th Eastern Mediterranean Chemical Engineering Conference that was supported by NSF.Intellectual Merit. The objectives of this research are to (1) establish effective characterization methods and approaches for the study vanadium oxide catalysts in the aqueous phase in the presence of HOOH and CH3OH environments with time resolved in situ and operando spectroscopy studies in the millisecond to minutes time scale (Raman, UV-vis, 51V NMR, EPR, rapid scan ATR-IR and quick-XANES/EXAFS) and (2) apply the advanced methodologies to study the VOx structures, oxidation states, reaction intermediates, mechanism, and kinetics of homogeneous vanadium haloperoxidase as a biocatalyst for the aqueous phase oxidation of methanol. Today, cutting edge catalysis research must combine the latest molecular spectroscopic characterization methodologies under relevant reaction conditions with state-of-the-art density functional theory (DFT). The rather complex V-containing enzymes in aqueous solution possess multiple oxygen functionalities (e.g., terminal V=O bonds, V-O-H bonds, bridging V-O-C bonds and peroxy V-O2 bonds) whose vibrational assignments are not straightforward without the assistance of DFT calculations. It is proposed that DFT calculations are performed on the V-containing enzymes in collaboration with Professor Onal's group at Middle Eastern Technical University (Anakara, Turkey) since only such research will provide molecular level insights into the reaction energetics of the different reaction pathways. Only combination of the molecular spectroscopic insights with the reaction pathways will allow the achievement of molecular structure reactivity relationships that is the ultimate goal of this research program.Broader Impact. The proposed research program extends the previous gas-solid CH3OH oxidation catalysis studies to liquid phase oxidation of CH3OH and also bridges inorganic catalysis with aqueous bioinorganic catalysis of enzymes. The development of time-resolved in situ and operando spectroscopic methodologies for investigating aqueous phase catalysis of inorganic and bioinorganic catalysts are significantly advanced by this undertaking and have wide reaching implications for numerous aqueous phase catalytic applications. Vanadium bioinorganic enzymes may provide a "green" alternative to traditional inorganic catalysts currently used in oxidation reactions and the new fundamental insights may assist in the development of improved pharmaceuticals, therapeutics, diabetes management and biocatalytic industrial applications. The Lehigh group significantly benefits from exposure to and training by a leading research group performing density functional theory calculations. The Turkish group significantly benefits by exposure to state-of-the-art experimental spectroscopic catalyst characterization methods and integration of theory with experiment.