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

该奖项由化学催化计划资助，科罗拉多矿业学院的Ryan理查兹教授将进行研究，旨在为纳米结构催化剂提供稳定性。这项工作是基于一种制备方法，使高度分散的“鲁棒”的金纳米粒子在溶胶-凝胶过程中的形态和多孔结构的控制。该系统的表征提供了存在纳米级金颗粒（4 nm）的证据，并且介孔网络是不间断的并且类似于SBA-15。该体系表现出更高的活性，正十六烷的氧化比系统与类似大小的金颗粒固定在介孔二氧化硅的孔网络。这表明插层材料的某些方面极大地影响催化性能（至少对于该反应）。此外，这些材料在高达750摄氏度的温度下表现出稳定性，没有颗粒生长的迹象，并且可回收利用。因此，所提出的工作的基础是追求的假设，即插层在介孔二氧化硅可以产生高活性和“强大的”催化系统，需要发展的基本理解，其制备，表征，并在选择催化反应的行为。尽管文献中已经描述了许多用于固定纳米级催化剂的方法，但是这种方法提供了独特的性质组合（即，可调孔隙率、热稳定性、增加的活性、广泛的适用性）。理想的“绿色”催化剂将使用空气作为氧化剂，在温和的条件下进行氧化反应，可回收利用，并避免浪费地添加还原剂和溶剂。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，该制备方法可以转移到其他金属或合金纳米颗粒以及离散分子。它代表了一种赋予化学和机械鲁棒性的新方法，这是目前纳米材料在催化中广泛应用的障碍。所设想的材料可以在苛刻的反应条件（温度和压力）下使用，在该条件下它们通常会烧结或聚集。催化过程具有重要的经济意义。开发具有改进的活性和选择性的“绿色”催化剂的能力可以积极地影响环境并改进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外展计划。

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.