Developing homogeneous catalytic systems for aerobic oxidative methylation with methane

在化学系化学催化项目的资助下，马里兰州大学帕克分校的Andrei Vedernikov博士正在开发新型铂催化剂，将甲烷从天然气转化为高附加值的化学品。空气中的氧气被用作反应物，因此这些反应避免了昂贵和潜在的有毒试剂。水是主要的反应副产物，因此几乎没有废物产生。甲烷以其化学惰性而闻名，开发更环保的工艺以将其经济可行地转化为高附加值产品是一项基本的化学挑战。为了解决这个问题，Vedernikov博士正在研究新型铂催化剂并设计新的催化剂。他正在利用理论和计算化学来探索合理的反应途径，并指导他的催化剂设计和实验工作。Vedernikov博士正在与来自低收入家庭的高中生合作。 这些学生对化学感兴趣，并已被美国化学学会（ACS Project SEED）的当地华盛顿特区部分选中。学生们在他的实验室实习，为这个项目的实验工作做出贡献。Vedernikov博士正在研究Shilov型系统，其中使用O2作为氧化剂生成亲电Pt（IV）Me中间体。在这项工作中使用两个互补的实验方法。一种依赖于氧化还原介体的使用，例如，Cu（II），而另一种利用Pt（II）R中间体的配体激活的O2活化。亲电Pt（IV）R中间体然后被各种亲核试剂（羧酸、胺等）拦截。以形成烃衍生物如季铵盐或酯，其被保护免于进一步氧化。Vedernikov博士正在开发一个基本的机理理解，即Pt（II）中心的配体环境如何使其对碳氢化合物C-H键和O2的反应性能够产生Pt（IV）R中间体。这两种方法的可行性最近已经在Vedernikov博士的小组中得到了证明。密度泛函理论被用来指导这些新系统的设计，并进行机械分析。开发更有效和环境友好的甲烷功能化方案具有变革性。 作为更广泛影响的一部分，Vedernikov博士正在与当地高中，本科生和研究生合作并在该项目中进行培训。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With funding from the Chemical Catalysis Program of the Division of Chemistry, Dr. Andrei Vedernikov of the University of Maryland College Park is developing novel platinum catalysts that convert methane from natural gas to high value-added chemicals. Oxygen from the air is used as a reactant and so these reactions avoid expensive and potentially toxic reagents Water is the major reaction by-product, so there is little waste produced. Methane is known for its chemical inertness and the development of greener processes for its economically-viable conversion to high-value added products is a fundamental chemical challenge. To tackle this problem, Dr. Vedernikov is studying novel platinum catalysts and designing new catalysts. He is taking advantage of theoretical and computational chemistry to explore plausible reaction pathways and guide his catalyst designs and experimental work. Dr. Vedernikov is working with high school students from low-income families. These students are interested in chemistry and have been selected by the local Washington D.C. section of the American Chemical Society (ACS Project SEED). The students intern in his lab, contributing to the experimental work in this project. Dr. Vedernikov is studying Shilov-type systems wherein electrophilic Pt(IV)Me intermediates are generated using O2 as the oxidant. Two complementary experimental approaches are used in this work. One relies on the use of redox mediators, e.g., Cu(II), while another utilizes a ligand-enabled O2 activation by Pt(II)R intermediates. The electrophilic Pt(IV)R intermediates are then intercepted by various nucleophiles (carboxylic acids, amines, etc.) to form hydrocarbon derivatives, such as quaternary ammonium salts or esters, that are protected from further oxidation. Dr Vedernikov is developing a fundamental mechanistic understanding of how the ligand environment at the Pt(II) center enables and tunes its reactivity toward both the hydrocarbon C-H bonds, and O2 to generate the Pt(IV)R intermediates. The viability of both approaches has been recently demonstrated in Dr. Vedernikov's group. Density functional theory is being used to guide the design of these novel systems and to carry out mechanistic analyses. The development of more efficient and environmentally benign protocols for methane functionalization is transformative. As a part of the broader impacts, Dr. Vedernikov is working with and training local high school, undergraduate and graduate students in this project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.