Resonance-Promoted Formic Acid Oxidation via Dynamic Electrocatalytic Modulation
Resonance-Promoted Formic Acid Oxidation via Dynamic Electrocatalytic Modulation
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DOI：
10.26434/chemrxiv.11972031
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发表时间：
2020-03
期刊：
影响因子：
12.9
通讯作者：
Joshua Gopeesingh;M. Ardagh;M. Ardagh;Manish Shetty;S. Burke;Paul J. Dauenhauer;Paul J. Dauenhauer;O. Abdelrahman;O. Abdelrahman
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文献类型：
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作者：
Joshua Gopeesingh;M. Ardagh;M. Ardagh;Manish Shetty;S. Burke;Paul J. Dauenhauer;Paul J. Dauenhauer;O. Abdelrahman;O. Abdelrahman
更快的催化剂能够更有效地将分子转化为有用的产品，并增强自然资源的可持续利用，这是举世公认的事实。然而，萨巴蒂尔原理定义的静态催化剂性能的限制催生了一种新的动态催化剂设计方法，即催化剂随时间在不同能量状态之间以足够高的共振频率振荡，以克服萨巴蒂尔“火山峰”。在这项工作中，动态催化共振的概念通过半连续多相流反应器内的 Pt 工作电极上水中甲酸的电催化氧化得到了实验证明。甲酸在 0.6 V (NHE) 下的稳态电氧化在室温下表现出约 1.0 s-1 的 CO2 形成最大周转频率 (TOF)。然而，电动势在 0.8 V 和开路之间通过方波以不同频率 (10-3 < f < 103 Hz) 振荡，将最佳 TOF 在 0.5 Hz 时增加到约 5 s-1。对于在 0 和 0.8 V 之间振荡的方波，在 100 Hz 谐振频率下观察到约 20 s-1 的更高 TOF。通过催化谐振，甲酸电氧化的速率增加超过恒电位条件一个数量级 (20 倍)，这被解释为通过非法拉第甲酸在低电位下脱水为表面结合的一氧化碳，然后在高潜力。
It is a truth universally acknowledged that faster catalysts enable the more efficient transformation of molecules to useful products and enhance the sustainable utilization of natural resources. However, the limit of static catalyst performance defined by the Sabatier principle has motivated a new approach to dynamic catalyst design, whereby catalysts oscillate with time between varying energetic states at sufficiently high resonant frequencies to overcome the Sabatier ‘volcano peak’. In this work, the concept of dynamic catalytic resonance was experimentally demonstrated via the electro-catalytic oxidation of formic acid in water on a Pt working electrode within a semi-continuous multi-phase flow reactor. Steady-state electro-oxidation of formic acid at 0.6 V (NHE) exhibited a maximum turnover frequency (TOF) of CO2 formation of ~1.0 s-1 at room temperature. However, oscillation of the electrodynamic potential between 0.8 V and open circuit via a square waveform at varying frequency (10-3 < f < 103 Hz) increased the optimal TOF to ~5 s-1 at 0.5 Hz. An even higher TOF of ~20 s-1 was observed at a resonant frequency of 100 Hz for a square waveform oscillating between zero and 0.8 V. The rate increase in formic acid electro-oxidation via catalytic resonance of more than an order of magnitude (20x) above potentiostatic conditions was interpreted to occur by non-faradaic formic acid dehydration to surface-bound carbon monoxide at low potentials, followed by surface oxidation and desorption to carbon dioxide at high potentials.