Joint Center for Artificial Photosynthesis and ‡Materials and Process Simulation Center, California Institute of Technology , Pasadena, California 91125, United States.
J Am Chem Soc. 2017 Jan 11;139(1):149-155. doi: 10.1021/jacs.6b07557. Epub 2016 Dec 28.
How to efficiently oxidize HO to O (oxygen evolution reaction, OER) in photoelectrochemical cells (PEC) is a great challenge due to its complex charge transfer process, high overpotential, and corrosion. So far no OER mechanism has been fully explained atomistically with both thermodynamic and kinetics. IrO is the only known OER catalyst with both high catalytic activity and stability in acidic conditions. This is important because PEC experiments often operate at extreme pH conditions. In this work, we performed first-principles calculations integrated with implicit solvation at constant potentials to examine the detailed atomistic reaction mechanism of OER at the IrO (110) surface. We determined the surface phase diagram, explored the possible reaction pathways including kinetic barriers, and computed reaction rates based on the microkinetic models. This allowed us to resolve several long-standing puzzles about the atomistic OER mechanism.
如何在光电化学电池（PEC）中有效地将 HO 氧化为 O（析氧反应，OER）是一个巨大的挑战，因为其电荷转移过程复杂、过电位高且易腐蚀。到目前为止，还没有一个 OER 机制能够从热力学和动力学两个方面进行全面的原子解释。IrO 是唯一已知的在酸性条件下具有高催化活性和稳定性的 OER 催化剂。这一点很重要，因为 PEC 实验通常在极端 pH 条件下运行。在这项工作中，我们通过在恒电位下进行的第一性原理计算与隐式溶剂化相结合，研究了 IrO（110）表面 OER 的详细原子反应机制。我们确定了表面相图，探索了可能的反应途径，包括动力学障碍，并基于微动力学模型计算了反应速率。这使我们能够解决关于原子 OER 机制的几个长期存在的难题。
