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教授在化学系化学催化（CAT）项目的支持下，开发了一种制备催化剂的新策略。该策略包括在金刚石表面形成精心而精确的聚合物结构，并使用这种修饰的表面来支持贵金属催化剂颗粒。相对于更常见的支撑材料，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点。进一步假设聚合物表面改性剂的结构和性质将提高催化剂的稳定性，并允许控制催化剂的反应性。从这项研究中获得的知识适用于由非贵金属和支持材料制成的催化剂，并适用于广泛的化学反应。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。与妇女获取方案和MESA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高中学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颗粒催化剂的多功能、坚固载体，并研究聚合物刷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所形成的纳米环境对纳米颗粒稳定性和催化性能的影响；(3)研究利用响应性聚合物修饰金属纳米催化剂的化学性质。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）和减少催化剂颗粒聚集。

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.