Outer coordination sphere optimization of electrocatalytic CO2 reduction

能源供应的安全性、可持续性和环境后果是现代社会的全球性问题。大自然已经优化了光合作用的机制，通过将二氧化碳和水转化为碳水化合物燃料来吸收和收获太阳能。然而，二氧化碳和水--地球上最普遍的化学物质--向可持续燃料来源的这种看似简单的转化仍然代表着当今科学的重大挑战之一。在这个项目中，马萨诸塞州波士顿大学的罗奇福德博士向大自然学习，开发出下一代分子催化剂，可以模拟光合作用，将二氧化碳和水高效转化为有用的燃料。就像我们在宏观世界中受到自身环境的强烈影响一样，二氧化碳和水的行为和性质在分子尺度上也对其局部环境非常敏感。 罗奇福德博士和他的学生利用“自组装”技术，灵感来自光合作用，利用二氧化碳和水的环境敏感性，以优化其可持续转化为燃料。从NSF化学部的化学催化计划的补助金丰富了许多马萨诸塞大学波士顿分校学生的本科生和研究生的经验，并对马萨诸塞大学波士顿分校的研究组合产生了重大的积极影响。该项目代表了一种新的方法，通过设计和合成的分子催化剂与工程的第二和外部配位领域提供选择性控制产品形成（一氧化碳与甲酸与氢气）的电催化二氧化碳还原。通过靶向第一行Mn（I）基过渡金属催化剂实现显著的智力价值，由此定制配体的第二配位和外配位范围，优化过渡态能量以促进质子偶联电子转移，从而降低关键速率决定步骤的活化能以最大化催化剂周转频率，并降低最小所需的过电位。罗奇福德博士和他的学生开发了尖端的催化剂设计方法，从合成到自组装，结合量身定制的电化学分析，这对采用纳米结构和电活性表面的许多研究领域产生了影响。这一领域的成功通知化学催化界更好地设计，控制和优化第一行过渡金属催化剂，以在可接近的过电位下选择性地转化二氧化碳。罗奇福德博士是一个教育的青年学者关于二氧化碳的环境影响，可再生能源的替代品，并在可再生能源技术的进步的强烈倡导者。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

The security of an energy supply, its sustainability and environmental consequences are global concerns in modern society. Nature has optimized the mechanism of photosynthesis to absorb and harvest solar energy by transforming carbon dioxide and water into carbohydrate fuels. Yet, this apparently simple transformation of carbon dioxide and water - the most ubiquitous chemicals on earth - to a sustainable fuel source still represents one of the grand challenges of science today. In this project, Dr. Rochford of University of Massachusetts Boston learns from nature and develops a next generation of molecular catalysts that can mimic photosynthesis to efficiently transform carbon dioxide and water into useful fuels. Just as we are strongly influenced by our own environment in a macroscopic world, the behavior and properties of carbon dioxide and water are also very sensitive to their local environment at a molecular scale. Dr. Rochford and his students utilize "self-assembly" techniques, inspired by photosynthesis, to leverage the environmental sensitivity of carbon dioxide and water to optimize their sustainable transformation into fuels. This grant from the Chemical Catalysis Program of the NSF Chemistry Division enriches the undergraduate and graduate experiences of many UMass Boston students and has a major positive impact on the UMass Boston research portfolio. This project represents a novel approach to electrocatalytic carbon dioxide reduction through the design and synthesis of molecular catalysts with engineered second- and outer-coordination spheres providing selective control over product formation (carbon monoxide vs. formic acid vs. hydrogen gas). Significant intellectual merit is achieved by targeting first-row Mn(I)-based transition metal catalysts whereby tailoring the second- and outer-coordination sphere of the ligand, transition-state energies is optimized to promote proton-coupled electron transfer, thus reducing activation energies for critical rate-determining steps to maximize catalyst turnover frequencies, and reduce the minimum required overpotential. Dr. Rochford and his students develop cutting-edge catalyst design methods, from synthesis to self-assembly, combined with tailored electrochemical analyses, which impacts on a host of research areas that employ nanostructured and electroactive surfaces. Success in this area informs the chemical catalysis community to better design, control and optimize first-row transition metal catalysts for selective carbon dioxide conversion at accessible overpotentials. Dr. Rochford is a strong advocate of education for young scholars regarding the environmental impacts of carbon dioxide, renewable energy alternatives, and advances in renewable energy technologies.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.