Montesano Cesare, Salden Toine P W, Martini Luca Matteo, Dilecce Giorgio, Tosi Paolo
Department of Physics, University of Trento, Trento, 38123, Italy.
Department of Applied Physics, Eindhoven University of Technology, Eindhoven, 5600MB, Netherlands.
J Phys Chem C Nanomater Interfaces. 2023 May 18;127(21):10045-10050. doi: 10.1021/acs.jpcc.3c02547. eCollection 2023 Jun 1.
Power-to-chemical technologies with CO as feedstock recycle CO and store energy into value-added compounds. Plasma discharges fed by renewable electricity are a promising approach to CO conversion. However, controlling the mechanisms of plasma dissociation is crucial to improving the efficiency of the technology. We have investigated pulsed nanosecond discharges, showing that while most of the energy is deposited in the breakdown phase, CO dissociation only occurs after an order of microsecond delay, leaving the system in a quasi-metastable condition in the intervening time. These findings indicate the presence of delayed dissociation mechanisms mediated by CO excited states rather than direct electron impact. This "metastable" condition, favorable for an efficient CO dissociation, can be prolonged by depositing more energy in the form of additional pulses and critically depends on a sufficiently short interpulse time.
以一氧化碳为原料的“电转化学”技术可循环利用一氧化碳，并将能量储存到增值化合物中。由可再生电力驱动的等离子体放电是一种很有前景的一氧化碳转化方法。然而，控制等离子体解离机制对于提高该技术的效率至关重要。我们研究了纳秒脉冲放电，结果表明，虽然大部分能量沉积在击穿阶段，但一氧化碳解离仅在微秒级延迟后才发生，在此期间系统处于准亚稳态。这些发现表明存在由一氧化碳激发态介导的延迟解离机制，而非直接电子碰撞。这种有利于高效一氧化碳解离的“亚稳态”条件可通过以额外脉冲形式沉积更多能量来延长，并且关键取决于足够短的脉冲间隔时间。
