NSF-DFG Echem: Spin-polarized electron currents for spin-selective electrocatalysis

本研究计划将探索和开发利用自旋极化电子的手性材料，以提高电催化中的化学选择性和能量效率。手性分子和手性材料优先传输自旋极化的电子，其中电子转移速率及其极化方向取决于材料的对映体形式。这项研究将考察产生自旋极化电子的新型手性金属氧化物电极材料，并评价它们作为电催化剂的有效性，正如我们在手性CuO的初步工作中所表明的那样。我们将使用放氧反应(OER)作为自旋选择电化学的通用指示剂，因为基态三重态氧的产生与过氧化氢和单重态氧等单态副产物之间的竞争。手性金属有机前驱体的液相电沉积法将制备手性第一排d-金属氧化物。将对纯金属氧化物和复合材料进行评估。在第二条线的研究中，假设超顺磁性氧化铁纳米颗粒在手性基质的支持下将成为更好的电催化剂。最后，手性超材料将被用来利用增强的(手性)等离子体吸收来产生自旋偏振光载流子。将其嵌入活性金属氧化物纳米颗粒或薄膜中，将对其电催化活性进行评价。在这项合作工作中，在匹兹堡研究了放氧反应，从而研究了催化活性，而在明斯特研究了手性材料发射的电子的自旋极化。这两个基团都以不同的技术对不同的手性金属氧化物材料的生长和表征做出了贡献。

This research program will explore and develop chiral materials for the use of spin-polarized electrons to improve the chemical selectivity and energy efficiency in electrocatalysis. Chiral molecules and chiral materials preferentially transmit spin polarized electrons, where the electron transfer rates and their polarization direction depend on the material’s enantiomeric form. The proposed research will examine new chiral metal oxide electrode material for generating spin polarized elec-trons and evaluate their efficacy as electrocatalysts, as has been shown by us in preliminary work to occur for chiral CuO. We will use the oxygen evolution reaction (OER) as a versatile indicator for spin selective electrochemistry because of the competition between the production of ground state triplet oxygen and singlet by-products like hydrogen peroxide and singlet oxygen. Chiral first-row d-metal oxides will be grown through liquid phase electrodeposition of chiral organometallic precursors. Pure metal oxides and composites will be evaluated. In a second line of research it is hypothe-sized that superparamagnetic iron oxide nanoparticles will become an even better electrocatalyst when supported by a chiral matrix. Finally, chiral metamaterials will be employed to make use of enhanced (chiral) plasmon absorption for the generation of spin polarized photocarriers. Embed-ded in active metal oxide nanoparticles or films their electrocatalytic activity will be evaluated. In this collaborative effort the oxygen evolution reaction and thus the catalytic activity is studied in Pittsburgh, while in Münster the spin polarization of electrons emitted from the chiral materials is determined. Both groups contribute with various techniques to the growth of different chiral metal oxide materials and to their characterization.