Tailoring the Nanoenvironment of Diamond-Supported Noble Metal Nanoparticles for Control of Catalysis

犹他大学的Jennifer Shumaker-Parry教授和Ilya Zharov教授得到了化学系化学催化(CAT)项目的支持，以开发一种新的催化剂制备策略。这一战略包括在钻石表面形成结构精细的聚合物，并使用这种经过修饰的表面来支撑贵金属催化剂颗粒。与更常见的载体材料相比，人造金刚石的低成本、化学稳定性和潜在的多功能性是吸引人的特征。进一步假设，聚合物表面改性剂的结构和性能将提高催化剂的稳定性，并允许控制催化剂的反应活性。从这项研究中获得的知识适用于由非贵金属和载体材料制成的催化剂以及广泛的化学反应。更广泛的商业影响是通过化学催化创造新产品和新技术的潜力。更广泛的教育影响是在跨学科的科学环境中培养研究生和本科生。与妇女机会方案和梅萨俱乐部合作开展的具体外联活动激发了来自代表性不足群体的初中生和高中生追求科学事业的兴趣。该项目的具体目标是：(1)研究合成纳米金刚石作为贵金属纳米粒子催化剂的多功能、坚固的载体，并研究聚合物刷子在这些载体上的生长；(2)探索不同长度、接枝密度、极性、结构和化学组成的聚合物刷子所创造的纳米环境对纳米粒子稳定性和催化性能的影响；以及(3)研究使用响应性聚合物来修饰金属纳米催化剂的化学。此外，还研究了聚合物刷结构的合理选择及其对催化剂纳米环境的控制，以提高催化剂的生产率(活性、周转率、寿命)，并最大限度地减少催化剂颗粒的聚集。

Professors Jennifer Shumaker-Parry and Ilya Zharov of the University of Utah are supported by the Chemical Catalysis (CAT) program in the Division of Chemistry to develop a new strategy for the preparation of catalysts. This strategy involves the formation of carefully and precisely structured polymers on diamond surfaces and the use of this modified surface to support precious metal catalyst particles. The low cost, chemical stability, and potential versatility of synthetic diamond are attractive features relative to more common support materials. It is further hypothesized that the structure and properties of the polymer surface modifiers will enhance catalyst stability and allow for control of catalyst reactivity. The knowledge gained from this research is applicable to catalysts made from non-precious metals and support materials and to a wide range of chemical reactions. The broader commercial impact is the potential to create new products and technologies via chemical catalysis. The broader educational impacts are the training of graduate and undergraduate students in an interdisciplinary scientific environment. Specific outreach activities in partnership with the ACCESS Program for women and with a MESA Club stimulate the interest of middle and high school students from underrepresented groups in pursuing science careers. The specific aims of the project are: (1) to investigate synthetic nanodiamond as a versatile, robust support for noble metal nanoparticle catalysts and study the growth of polymer brushes on these supports; (2) to explore the effect of the nanoenvironment created by polymer brushes with varying length, grafting density, polarity, structure and chemical composition on nanoparticle stability and catalytic performance, and (3) to study the use of responsive polymers to modify metal nanocatalyst chemistry. In addition, judicial selection of polymer brush architecture and its control of the catalyst nanoenvironment is investigated to improve catalyst productivity (activity, turnover, life time) and minimize catalyst particle aggregation.