Selectivity Control under Dynamic CO2 Electroreduction Conditions

动态 CO2 电还原条件下的选择性控制

• 批准号: 406944504
• 负责人: Professor Dr. Olaf Magnussen
• 金额: --
• 依托单位: Institut für Experimentelle und Angewandte Physik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/406944504?language=en
• 关键词: Selectivity; Control; under; Dynamic; CO2

Electroreduction of carbon monoxide (CO2RR) on Cu-based electrocatalysts can provide significant yields of multi-carbon (C2+) products and thus opens a promising way for its conversion into valuable feedstock chemicals and fuels. Dynamic (potential pulsed) CO2RR has recently received significant attention, as it allows to periodically generate/restore distinct catalyst states and morphological motifs in situ, offering new possibilities for tuning the product selectivity, and regenerating poisoned catalyst surfaces. However, the active catalyst state and its dynamic evolution are still unclear and the detailed mechanisms of dynamic CO2RR require clarification.We will explore enhancing the CO2RR selectivity towards C2+ products using dynamic reaction conditions. Optimized conditions will be identified from extensive electro¬catalytic studies and studied in-depth by operando time-resolved methods. We aim to identify the influence of the potentiodynamic charac¬teris¬tics (pulse shape, range, and period) on the catalyst selectivity. By varying the anodic potential (to oxidizing and non-oxidizing conditions) and time regime (from ms to hours) different modifications of the electrode’s state are possible, such as changes in the surface charge, adsorbed species, redox state, and surface morphology. We will identify how this can improve the evolution of the C2+ selectivity and overcome catalyst poisoning to ensure stable catalyst activitiy and selectivity.Apart from pure Cu catalysts (Cu2O nanocubes, Cu single crystals) we will also study those decorated with secondary metal nanoparticles (Ag, Au, Zn) for tandem catalysis. Further-more, we will explore the selective promotion/inhibition of mechanistic pathways by chemical species (alkali cations, halide anions). For both, an increase in C2+ selectivity under potentiostatic conditions has been shown and we will extend these studies to the potentiodynamic case. For an improved understanding, the potential-dependent adsorption geometries, surface concentrations of the involved species (intermediates, inhibitors/promotors) and their influence on the Cu structure will be studied.For these studies, the FHI and CAU teams will employ their complementary expertise in operando techniques comprising a variety of spectroscopic (Raman, XAS) and X-ray scattering (powder and surface X-ray diffraction) as well as microscopic (STM/AFM) methods. These will provide comprehensive insights into the catalyst structure, adsorption geometry of important reaction intermediates (CO) and active spectator species as well as the dynamic changes of the catalyst’s properties. These insights will be directly correlated to the catalytic activity and C2+ selectivity. Furthermore, the FHI group will transfer the obtained understanding to electrolyzer-like gas-fed flow cells. Thereby, we will significantly contribute to a fundamental understand on the C2+ formation during CO2RR and especially, under potentiodynamic reaction conditions.

在铜基电催化剂上电还原一氧化碳 (CO2RR) 可以产生大量多碳 (C2+) 产品，从而为其转化为有价值的原料化学品和燃料开辟了一条有前途的途径。动态（电势脉冲）CO2RR 最近受到了广泛关注。值得注意的是，它允许在原位定期生成/恢复不同的催化剂状态和形态图案，为调整产物选择性和再生有毒催化剂表面提供了新的可能性。状态及其动态演化仍不清楚，动态 CO2RR 的详细机制需要澄清。我们将利用动态反应条件探索 CO2RR 对 C2+ 产物的选择性，将从广泛的电催化研究中确定优化条件，并通过操作时间进行深入研究。我们的目标是通过改变阳极电位来确定动电位特性（脉冲形状、范围和周期）对催化剂选择性的影响。氧化和非氧化条件）和时间范围（从毫秒到小时）可以对电极状态进行不同的修改，例如表面电荷、吸附物质、氧化还原状态和表面形态的变化，我们将确定如何改进。 C2+选择性的演变，克服催化剂中毒，确保稳定的催化剂活性和选择性。除了纯Cu催化剂（Cu2O纳米立方体、Cu单晶）外，我们还将研究那些二次金属修饰的催化剂此外，我们将探索化学物质（碱金属阳离子、卤化物阴离子）对机械途径的选择性促进/抑制，在恒电位条件下，C2+ 选择性有所增加。已被证明，我们将把这些研究扩展到动势动力学案例，以更好地理解电势依赖性吸附几何形状、所涉及物质的表面浓度（中间体、将研究抑制剂/促进剂）及其对 Cu 结构的影响。在这些研究中，FHI 和 CAU 团队将利用他们在操作技术方面的互补专业知识，包括各种光谱（拉曼、XAS）和 X 射线散射（粉末和表面X射线衍射）以及显微（STM/AFM）方法将提供对催化剂结构、重要反应中间体（CO）和活性观察物种的吸附几何形状以及动态变化的全面见解。这些见解将与催化活性和 C2+ 选择性直接相关，FHI 小组将把获得的理解转移到类似电解槽的气体供给流动池中，从而为对催化剂的基本理解做出重大贡献。 CO2RR 过程中，尤其是动电位反应条件下，C2+ 形成。