CAS: Collaborative Research: New Hybrid Catalysts for Sustainable Cross-Coupling Reactions: Using Atomic Layer Deposition to Immobilize and Enhance Molecular Catalysts

像塑料和药物这样的化学物质对现代生活是必不可少的。然而，大规模的化学生产可能需要大量能源，并可能产生有毒废物。催化剂可以减少生产化学品所需的能源，减少浪费，并为化学品制造商节省大量成本。该项目的目标是开发新的催化剂，以制造特定的化学产品，同时减少能源消耗和有毒废物的产生。这项研究正在开发既有选择性又容易回收重复使用的先进催化剂。此外，这些催化剂正被用于无毒和无腐蚀性的液体，如水。因此，这些催化剂使化学生产对工人来说更安全，并减少了对周围社区和环境的危害。这项研究计划正在研究如何设计这些催化剂用于化学反应，否则很难在危害较小和能源高效的条件下实现这些反应。该项目将南卡罗来纳大学的化学催化专家Aaron Vannucci博士和佐治亚理工学院的材料合成专家Mark Losego博士配对。由该项目资助的博士生正在接受这两个领域的联合培训。这种技能的交流正在扩大对这两个群体的学生的科学培训，并将影响两所大学未来的学生。万努奇博士正在积极开展外展项目，对高中教师进行化学科学方面的培训。洛塞戈博士正在管理一家由本科生运营并为本科生服务的材料分析机构。这些项目在多个层面上促进了对STEM领域的兴趣、教育和培训。在该项目期间交流的技能被用来进一步加强这些动手STEM培训计划。南卡罗来纳大学的Aaron Vannucci博士和佐治亚理工学院的Mark Losego博士在化学催化计划和既定的促进竞争研究计划的联合资助下，正在合作开发关于新型混合催化剂的知识，这种催化剂可以将非贵金属分子催化剂固定在氧化物纳米颗粒载体上，通过原子层沉积(ALD)沉积纳米金属氧化物覆盖层。通过简单的过滤和洗涤，这些分子/多相催化剂已经表现出良好的铃木交叉偶联反应的可回收性。人们正在进行物理化学研究，不仅要了解ALD层在物理上稳定粒子表面催化剂分子的能力，还要了解ALD金属氧化物覆盖层与分子催化剂之间的协同化学作用，从而提高催化活性。具体地说，研究人员正在开发使用ALD处理和化学来控制活性部位周围的局部几何和化学环境的策略，以实现与医学研究和药物发现相关的困难的C(SP3)-C(SP3)和立体收敛偶联反应。这些混合催化剂遵循许多绿色化学原则，包括使用非贵金属，在非腐蚀性水溶液中操作，以及易于分离和回收。该计划还支持在合作机构扩大学生和研究人员的交流，以在化学催化和气相沉积处理的正交科学学科中交叉培训博士生。这些知识和技能正在每个实验小组中制度化，并广泛影响当前和未来几代学生。在这些交流中，访问调查人员正在制定计划，以进一步加强现有的外展和培训计划，支持实践本科教育和高中教师培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Chemicals like plastics and medicines are essential to modern life. However, large-scale chemical production can require large amounts of energy and can create toxic waste. Catalysts can reduce the energy needed to produce chemicals, reduce waste, and provide large cost savings for chemical manufacturers. The goal of this project is to develop new catalysts to make specific chemical products while also reducing both energy usage and the creation of toxic waste. This research is developing advanced catalysts that are both selective and easily recovered for repeated use. Further, these catalysts are being used in non-toxic and non-corrosive liquids, like water. Thus, these catalysts make chemical production safer for workers and reduce hazards to surrounding communities and the environment. This research program is studying how to design these catalysts for use in chemical reactions that are otherwise difficult to achieve under less hazardous and energy efficient conditions. This program pairs Dr. Aaron Vannucci at the University of South Carolina, an expert in chemical catalysis, with Dr. Mark Losego at the Georgia Institute of Technology, an expert in materials synthesis. Ph.D. students funded by this project are being jointly trained in both fields. This exchange of skills is expanding the scientific training for students in both groups and will impact future students at both universities. Dr. Vannucci is actively running outreach programs to train high school teachers in the chemical sciences. Dr. Losego is directing a materials analysis facility run by and for undergraduate students. These programs promote interest, education, and training in STEM fields at multiple levels. Skills exchanged during this project are being used to further enhance these hands-on STEM training programs. With joint funding from the Chemical Catalysis Program and the Established Program to Stimulate Competitive Research, Dr. Aaron Vannucci from the University of South Carolina and Dr. Mark Losego from the Georgia Institute of Technology are collaboratively developing knowledge about new hybrid catalysts that immobilize non-precious metal molecular catalysts on oxide nanoparticle supports with nano-scale metal oxide over-layers deposited via atomic layer deposition (ALD). These molecular/heterogeneous catalysts have already shown excellent recyclability for Suzuki cross-coupling reactions via simple filtration and washing. Physicochemical studies are being conducted to understand not only the ability for ALD layers to physically stabilize the catalyst molecules on the particle surfaces but also the synergistic chemical interactions between the ALD metal oxide over-layer and molecular catalyst that lead to enhanced catalytic activity. Specifically, the investigators are developing strategies using ALD processing and chemistry to control the local geometric and chemical environment around the active site to achieve difficult C(sp3)-C(sp3) and stereoconvergent coupling reactions relevant to medical research and drug discovery. These hybrid catalysts adhere to many green chemistry principles including the utilization of non-noble metals, operation in non-corrosive, aqueous solvents, and ease in separation and recyclability. This program also supports extended student and investigator exchanges at the collaborative institutions to cross-train the Ph.D. students in orthogonal scientific disciplines of chemical catalysis and vapor deposition processing. These knowledge and skill sets are being institutionalized in each lab group and broadly impact current and future generations of students. During these exchanges the visiting investigators are developing programs to further enhance existing outreach and training programs that support hands-on undergraduate education and high school teacher training.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.