Mechanism and kinetics of electrocatalytic reactions

本研究的目的是研究氢的吸附、吸收和析出的电催化反应，金属氢化物的形成机理和动力学，以及多孔电极的模拟。这项研究将有助于更好地理解这些反应，并开发出更好的储氢和电解水电极材料。本论文的研究内容包括：1.吸氢机理和动力学：我们前期的研究表明，直接吸氢机理是主要的反应途径，而通过吸附氢气的反应要慢得多。这一过程将在其他铂合金上进一步研究，如Pd-Rh，Pd-Ru等，从电催化的角度来看，这些合金是非常重要的。将研究氢的吸附以及不同毒物对吸氢过程的影响。将测定吸附等温线和氢的吸附和吸收动力学。应该强调的是，几种氢吸附毒物作为吸氢的促进剂，增加了这一过程的动力学。这些最初在硫酸存在下研究的过程将扩展到未吸附的高氯酸和碱性溶液。吸附过程的动力学和热力学：氢吸附反应是最简单的电催化反应。本实验室已研究过的在多晶铂上的动力学将利用本实验室最近发展起来的双电极技术在其他贵金属(多晶Rh、Ru、Ir)、合金(Pd-Rh、Pd-Ru、Pd-Ir)和单晶金属上进一步研究。多孔电极的建模：为了验证理论，我们将在具有明确定义的多孔几何结构的多孔电极(如刷状电极)上研究简单氧化还原反应的动力学。

The purpose of the proposed research is to study electrocatalytic reactions of hydrogen adsorption, absorption and evolution, mechanism and kinetics of metal hydride formation, and modeling of porous electrodes. This study will lead to a better understanding of these reactions and to develop better electrode materials for hydrogen storage and water electrolysis. This research includes:1. Mechanism and kinetics of hydrogen absorption: Our earlier studies suggest that the direct absorption mechanism is the main reaction path and that going through adsorbed hydrogen is much slower. This process will be further studied on other Pt alloys as Pd-Rh, Pd-Ru, etc., which are very important from the electrocatalytic point of view. Adsorption of H and the influence of different poisons on the H absorption processes will be studied. Adsorption isotherms and the kinetics of hydrogen adsorption and absorption will be determined. It should be stressed that several poisons of hydrogen adsorption act as promoters of hydrogen absorption increasing the kinetics of this process. These processes, studied initially in the presence of sulfuric acid will be extended to the non adsorbed perchloric acid and to alkaline solutions.2. Kinetics and thermodynamics of adsorption processes: Hydrogen adsorption reaction is the simplest electrocatalytic reaction. Its kinetics already studied in our laboratory on polycrystalline Pt will be further studied on other noble metals (polycrystalline Rh, Ru, Ir), alloys (Pd-Rh, Pd-Ru, Pd-Ir) and monocrystalline metals using the twin electrode technique developed recently in our lab.3. Modeling of porous electrodes: The kinetics of simple redox reactions will be studied on porous electrodes characterized by the well defined porous geometry (e.g. brush electrodes) to test the theory.