CAREER: Heterogeneous Molecular Catalysts for Electrochemical CO2 Reduction

二氧化碳(CO2)是一种温室气体，是燃烧化石燃料的废物，也是其他工业过程的副产品。将二氧化碳转化为燃料和化学产品减少了二氧化碳排放，并为燃料和化学原料提供了一种替代的碳来源。实现这一目标的一种方法是使用电力和一种被称为催化剂的“辅助”分子，在一种名为“电催化”的化学过程中找到一条能源高效的反应路径。与电催化二氧化碳还原相关的两大挑战是反应缓慢和难以控制反应产物的分布。在这个项目中，王海良博士正在开发一种新的高效催化剂，用于二氧化碳快速、选择性地电化学还原为碳氢化合物。这些材料的催化中心本质上是分子的，因此可以利用合成化学来精确地定制催化剂结构。在十亿分之一米(纳米级)的水平上进一步优化结构，以提高其催化性能。催化剂不溶于电解液，因此很容易分离。王博士积极参与外展活动，以他的研究为基础，促进学生对科学、技术、工程和数学(STEM)学科的参与。这些活动包括以耶鲁大学西校区能源科学研究所为基础的名为“催化可持续能源未来”的新推广计划，旨在改善不同类型的大学预科学生的教育，并鼓励他们对STEM职业的兴趣。在化学系化学催化项目的资助下，耶鲁大学王海良博士正在设计基于金属卟啉分子的多相电催化剂材料，用于将二氧化碳高效还原为碳氢化合物。该方法结合了分子的原子级结构可调整性和多相催化剂材料的实际操作优势，提供了具有更高性能的新型电催化剂材料。通过不同的金属离子、引入电子取代基、引入质子供体基团和设计选择性的中间稳定结构来定制金属卟啉的分子结构。通过将金属-卟啉分子锚定在辅助纳米结构上，进一步提高了电催化性能。电化学条件下的原位和操纵性X射线吸收光谱研究以及理论计算和计算模拟也被用来解释反应机理。王博士积极参与外展活动，以他的研究为基础，促进学生对STEM学科的参与。这些活动包括以耶鲁大学西校区能源科学研究所为基础的名为“催化可持续能源未来”的新推广计划，旨在改善不同类型的大学预科学生的教育，并鼓励他们对STEM职业的兴趣。

Carbon dioxide (CO2) is a greenhouse gas that is a waste product of burning fossil fuels and is a byproduct of other industrial processes. Converting the carbon dioxide to fuels and chemical products reduces CO2 emissions and provides an alternative source of carbon for fuels and chemical feedstocks. One way this can be accomplished is using electricity and a "helper" molecule known as a catalyst to find an energy efficient reaction path in a chemical process called electrocatalysis. Two major challenges associated with electrocatalytic CO2 reduction are that the reactions are slow and that it is difficult to control the distribution of reaction products. In this project, Dr. Hailiang Wang is developing a new category of highly efficient catalysts for fast and selective electrochemical reduction of carbon dioxide to hydrocarbons. The catalytic sites of these materials are molecular in nature, so that synthetic chemistry can be utilized to accurately tailor the catalyst structures. The structures are further optimized at one the billionth of a meter level (the nanometer scale) to enhance their catalytic performance. The catalysts are insoluble in the electrolyte solution so that they can be easily separated. Dr. Wang is actively engaged in outreach activities that build upon his research to promote engagement of students in science, technology, engineering and mathematics (STEM) disciplines. These activities, which include a new outreach program named "Catalyzing a Sustainable Energy Future" based on the Energy Sciences Institute on Yale West Campus, are directed at improving the education of a diverse body of pre-college students and encouraging their interest in STEM careers. With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Hailiang Wang of Yale University is designing metal-porphyrin molecular based heterogeneous electrocatalyst materials for efficient CO2 reduction to hydrocarbons. The approach combines the atomic-level structural tunability of molecules with the practical handling advantages of heterogeneous catalyst materials, to render new electrocatalyst materials with higher performance. The metal-porphyrin molecular structures are tailored by varying metal ions, introducing electronic substituents, incorporating proton donating groups, and designing selective intermediate stabilizing structures. The electrocatalytic performance are further enhanced by anchoring the metal-porphyrin molecules onto ancillary nanostructures. In-situ and operando X-ray absorption spectroscopic studies under electrochemical conditions and theoretical calculations and computational simulations are also performed to elucidate the reaction mechanisms. Dr. Wang is actively engaged in outreach activities that build upon his research to promote engagement of students in STEM disciplines. These activities, which include a new outreach program named "Catalyzing a Sustainable Energy Future" based on the Energy Sciences Institute on Yale West Campus, are directed at improving the education of a diverse body of pre-college students and encouraging their interest in STEM careers.