(666c) Rate Enhanced and Energy-Efficient Electrocatalytic Oxidation of Formic Acid: A Dynamic Duo for Sustainable Catalysis

Catalysis is a rapidly evolving field that requires the continuous search for new and sustainable catalysts that involve developing new materials, which can be expensive and time-consuming. Dynamic catalysis is a newly explored field that tackles these limitations by using potential modulation to access higher rates and surpass the static Sabatier maximum. This is achieved by providing elementary steps such as adsorption, reaction, and desorption, with the energetic environment needed to maximize the overall catalytic turnover. Here, we explore the electro-oxidation of formic acid over platinum, an extensively studied chemistry with well-defined mechanisms, to investigate the thermodynamic properties and energetic costs of dynamic systems that need to be considered, along with the challenges that may arise when implementing potentiodynamic methods. The oscillations were applied in square-wave form from 0 V to 0.8 V vs. NHE with equal time spent at each potential (50% duty cycle). Based on kinetic data, it was found that at a frequency of 0.1 Hz, the rate of CO₂ formation was 8.5 times higher than the static Sabatier maximum condition, which was observed at 0.6 V vs NHE. Correlations were established from fundamental thermodynamic concepts, as well as kinetic and electrochemical measurements, to examine the faradaic (ε_FE), thermodynamic (ε_TE), and energy efficiency (ε_EE) related to potential oscillations. According to the established correlations, it was found that potential oscillations have minimal effects on both the faradaic and energy efficiencies, as shown in Figure 1A. Additionally, fundamental calculations showed that the thermodynamic efficiency increased to 32% compared to the static maximum of 18% (Figure 1B), with the increase being frequency independent.

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