Using detailed kinetic sensitivity analyses and dynamic computational modeling, our study confirms that carefully engineered potential cycling significantly improves the cycle-averaged turnover frequency (TOF) for formic acid oxidation on platinum electrodes compared to steady-state conditions. By minimizing mass transport limitations in highly acidic environments, intrinsic kinetic mechanisms and reaction pathway dynamics are clearly identified.
Our results illustrate a distinct potential-dependent surface environment at steady state: at lower potentials, FA dehydration is favorable, resulting in substantial CO surface coverage; at elevated potentials, dehydrogenation without breaking CO bonds becomes dominant resulting in a high bidentate formate coverage, ultimately poisoning the surface at high potentials. Dynamic modulation strategically circumvents steady state constraints and exploits access to intermediate surface coverages. By dynamically traversing different coverages and kinetically limited regimes, the reaction reaches transient rates that substantially exceed steady-state catalytic performance.
Furthermore, optimal modulation of parameters—such as cycling frequency, amplitude, and potential profile—are identified to maximize catalytic efficiency and energy conversion. Integrating fundamental mechanistic insights with practical dynamic modulation strategies represents a significant advancement toward viable formic acid-based electrochemical energy technologies, promising transformative benefits for sustainable energy conversion.
References:
[1] Gopeesingh, J., Ardagh, M. A., Shetty, M., Burke, S. T., Dauenhauer, P. J., Abdelrahman, O. A. (2020). ACS Catalysis 10(17), 9932–9942.