Preparation method that enables control of morphology and porous structure with highly dispersed "robust" metal nanoparticles

利用高度分散的“鲁棒”金属纳米粒子控制形态和多孔结构的制备方法

• 批准号: 1214068
• 负责人: Ryan Richards
• 金额: $ 38.81万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1214068&HistoricalAwards=false
• 关键词: Preparation; method; enables; control; morphology

With this award funded by the Chemical Catalysis Program, Professor Ryan Richards of the Colorado School of Mines will perform research directed towards imparting stability to nanostructured catalysts. The work is based upon a preparation method that enables control of the morphology and porous structure of highly dispersed "robust" gold nanoparticles in the sol-gel process. Characterization of this system provided evidence of the presence of nanoscale gold particles (4nm) and that the mesoporous network is uninterrupted and analogous to SBA-15. This system demonstrated higher activity for the oxidation of n-hexadecane than systems with similar size gold particles immobilized in the pore network of mesoporous silica. This suggests that some aspect of the intercalated material greatly influences the catalytic properties (at least for this reaction). Additionally, these materials demonstrated stability at temperatures up to 750 degrees Centigrade without evidence of particle growth and were recyclable. Thus, the basis for the proposed work is to pursue the hypothesis that intercalation in mesoporous silica can yield highly active and "robust" catalytic systems entailing development of a fundamental understanding of their preparation, characterization, and behavior in select catalytic reactions. Although numerous approaches for the immobilization of nanoscale catalysts have been described in the literature, this approach offers a unique combination of properties (i.e., tunable porosity, thermal stability, increased activity, broad applicability). An ideal "green" catalyst would use air as the oxidant under mild conditions for oxidation reactions, be recyclable and avoid the wasteful addition of reducing agents and solvents. This work aims to accomplish all of these goals and represents the conceptual foundation for the ability to form intercalated nanostructures. Further, the preparation methodology may be transferable to other metal or alloy nanoparticles as well as discrete molecules. It represents a new approach to imparting chemical and mechanical robustness, a current impediment to the broad application of nanoscale materials in catalysis. The envisioned materials may be employed under harsh reaction conditions (temperature and pressure) in which they would typically sinter or aggregate. Catalytic processes are of vital economic importance. The ability to develop 'green' catalysts with improved activity and selectivity may positively impact the environment and improve the economic feasibility and resource efficiency of important industrial processes. The project includes student training and outreach programs to K-12.

该奖项由化学催化计划资助，科罗拉多矿业学院的瑞安·理查兹教授将进行旨在赋予纳米结构催化剂稳定性的研究。这项工作是基于一种制备方法，该方法能够在溶胶-凝胶过程中控制高度分散的“健壮”金纳米颗粒的形态和多孔结构。该体系的表征提供了纳米级金颗粒(4 Nm)存在的证据，并且介孔网络是不间断的，类似于SBA-15。该体系对正十六烷的氧化活性高于相同尺寸的金颗粒固定在介孔二氧化硅孔道网络中的体系。这表明，插层材料的某些方面对催化性能(至少对该反应)有很大影响。此外，这些材料在高达750摄氏度的温度下表现出稳定性，没有颗粒生长的证据，并且可以回收。因此，拟议工作的基础是追求这样一个假设，即插层在介孔二氧化硅中可以产生高度活性和“健壮”的催化体系，从而需要对其制备、表征和在选择性催化反应中的行为有一个基本的了解。虽然文献中已经描述了许多纳米级催化剂的固定化方法，但这种方法提供了一种独特的性能组合(即，可调的孔隙率、热稳定性、提高的活性、广泛的适用性)。理想的“绿色”催化剂应以空气为氧化剂，在温和的条件下进行氧化反应，可回收利用，避免添加大量的还原剂和溶剂。这项工作旨在实现所有这些目标，并代表了形成插层纳米结构的能力的概念基础。此外，该制备方法也可用于其他金属或合金纳米颗粒以及离散分子。它代表了一种新的方法来赋予化学和机械的健壮性，目前阻碍了纳米材料在催化中的广泛应用。设想的材料可以在苛刻的反应条件(温度和压力)下使用，在这种条件下，它们通常会烧结或聚集。催化过程具有极其重要的经济意义。开发具有更高活性和选择性的绿色催化剂的能力可能会对环境产生积极影响，并提高重要工业过程的经济可行性和资源效率。该项目包括学生培训和K-12的外展计划。