NIRT: Tuning the Electronic and Molecular Structures of Catalytic Active Sites with Oxide Nanoligands

建议标题：NIRT：使用氧化物纳米配体调整催化活性中心的电子和分子结构建议编号：CTS-0609018主要研究员：以色列E.WachsInstitution：LeHigh University分析(决定的基本原理)：该建议是响应纳米科学和工程倡议，NSF 05-610，NIRT类别而收到的。多相催化剂是促进表面化学反应的固体物质，其表面的纳米尺度和化学特性影响催化剂的活性、选择性和寿命。催化剂的纳米工程为更深入地了解催化活性表面位置的性质提供了巨大的潜力，并为改善环境、能源、石化、制药和食品工业以及最近在国土安全方面的催化剂性能提供了机会。这项建议具体描述了一项为期四年的研究和教学计划，重点是调整氧化物纳米配体的电子和分子结构，以及它们对分子工程支撑金属氧化物催化活性中心催化性能的影响。本项目将系统地研究在催化活性金属氧化物-载体相互作用的临界0.5-10 nm范围内的氧化物衬底纳米结构对生成的电子结构、分子结构和催化性能的影响。一系列模型支载的催化剂将被分子工程设计，以允许催化活性中心和氧化物纳米配体的变化。通过控制纳米配体的尺寸、电子结构、分子结构、组成(CeO2、TiO2、ZrO2及其混合物)和催化活性中心(酸性WOx、碱性BaOx、氧化还原VOx及其混合物)来调节催化活性/选择性。这些纳米负载催化剂将在惰性无定形硅质基质中被活体合成，以控制氧化物纳米配位体的尺寸及其分布。这些新型催化材料将利用现有最先进的分子水平原位显微和光谱技术，在不同的反应条件下进行电子、分子和化学表征，以确定其基本的电子/分子结构-活性/选择性关系。这些新的见解将被用来开发分子水平的模型，捕捉氧化物纳米配体的电子和分子特征对固定在这些纳米配体底物上的催化活性中心的化学性质的影响。这些理论模型随后将被用于指导先进的负载型催化材料的分子设计，通过调整氧化物纳米配体的催化活性中心的电子和分子结构来实现当前工业上具有挑战性的催化应用。这一基本信息将允许建立氧化物纳米配基结构域大小与一系列重要催化反应的负载型催化活性中心电子和分子结构之间的分子水平关系。这些分子水平的关系将导致纳米和传统负载型催化剂的新理论模型的发展，以及此类多组分设计材料的非催化材料的应用。这些新的见解将有助于“下一代”负载型催化剂的分子设计，其中氧化物支撑型纳米配位体结构域的大小是调整负载型催化活性中心的物理和化学性质的关键因素。教育和推广计划包括本科生和研究生培训、高中教师培训、年度现场轮换研讨会，以及最先进的显微镜和光谱学学校。工业合作伙伴英国石油公司已同意将在这项研究计划中发现的有前景的先进催化材料商业化。

AbstractProposal Title: NIRT: Tuning the Electronic and Molecular Structures of Catalytic Active Sites with Oxide Nanoligand Proposal Number: CTS-0609018Principal Investigator: Israel E. WachsInstitution: Lehigh UniversityAnalysis (rationale for decision):This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 05-610, category NIRT. Heterogeneous catalysts are solid substances that accelerate chemical reactions at the surface, whereby the nanoscale and chemical features of the surface affect the activity, selectivity, and longevity of the catalyst. Nanoscale engineering of the catalyst offers tremendous potential for understanding more deeply the nature of the catalytic active surface site, and offers the opportunity to improve catalyst performance in environmental, energy, petrochemical, pharmaceutical and food industries, and more recently in homeland security. This proposal specifically describes a four-year research and teaching plan focused on tailoring the electronic and molecular structures of oxide nanoligands and their resulting impact on the catalytic performance of molecularly engineered supported metal oxide catalytic active sites. This project will systematically examine the influence of the oxide substrate nanostructure in the critical 0.5-10 nm range for the catalytic active metal oxide-support interaction upon the resultant electronic structures, molecular structures and catalytic properties. A series of model supported catalysts will be molecularly engineered to allow for variation of the catalytic active sites and oxide nanoligands. The nanoligand dimension, electronic structure, molecular structure, composition (CeO2, TiO2, ZrO2, and their mixtures) and the catalytic active sites (acidic WOx, basic BaOx, redox VOx, and their mixtures) will be controlled to tune the catalytic activity/selectivity. These nano-supported catalysts will be synthesized in vivo within inert amorphous siliceous matrices to control the oxide nanoligand domain size and its distribution. These novel catalytic materials will be electronically, molecularly, and chemically characterized with the most advanced state-of-the-art molecular level in situ microscopic and spectroscopic techniques currently available, and under different reaction conditions, to determine their fundamental electronic/molecular structure-activity/selectivity relationships. These new insights will be employed to develop molecular level models that capture the influence of oxide nanoligand electronic and molecular characteristics on chemical properties of catalytic active sites anchored on such nanoligand substrates. The theoretical models will subsequently be used to guide the molecular design of advanced supported catalytic materials by tuning the electronic and molecular structures of catalytic active sites with the oxide nanoligands for several challenging catalytic applications of current industrial interest. This fundamental information will allow the establishment of molecular level relationships between oxide nanoligand domain size and supported catalytic active site electronic and molecular structures for a range of important catalytic reactions. These molecular level relationships will lead to the development of new theoretical models for nano and conventional supported catalysts, as well as non-catalytic materials applications, of such multicomponent designed materials. The new insights will assist in the molecular design of 'next generation' supported catalysts where the oxide support nanoligand domain size is a critical factor in tailoring physical and chemical properties of supported catalytic active sites. The educational and outreach programs include undergraduate and graduate student training, high school teacher training, an annual site-rotating workshop, and state-of-the-art microscopy and spectroscopy schools. An industrial partner, BP, has agreed to pursue commercialization of promising advanced catalytic materials that will be discovered in the course of this research program.