Thermodynamic Discrimination Between Energy Sources for Chemical Reactions


Chemical transformations traverse large energy differences, yet the choice of energy source to drive a chemical reaction is often decided on a case-by-case basis; there is no fundamentally-driven, universal framework with which to analyze and compare the choice of energy source for chemical reactions. In this work, we present a reaction-independent expression for the equilibrium constant as a function of temperature, pressure, and voltage. With a specific set of axes, all reactions can be represented by a single (x,y) point and a quantitative divide between electrochemically and thermochemically driven reactions is visually evident. In addition, we show that our expression has a strong physical basis in work and energy fluxes to the system, although more specific data about reaction operation is necessary to provide a quantitative energy analysis. Overall, this universal equation and facile visualization of chemical reactions enables quick and informed justification for electrochemical versus thermochemical energy sources without knowledge of detailed process parameters.


Supplementary material