Quantitative Physical Chemistry of Heterogeneous Catalysis: From Microkinetics to Multiphysics Reactor Design

Abstract Quantitative understanding of catalysis requires more than comparison of apparent activity. It begins by establishing whether a measured rate represents intrinsic surface chemistry or is influenced by mass transfer, heat transfer, reactor geometry, or catalyst evolution. Thermocatalysis developed a rigorous physical-chemistry framework for making this distinction and for describing intrinsic rates through microkinetic analysis, in which adsorption, surface reaction, desorption, coverage, and kinetically controlling elementary steps are evaluated using independently measurable parameters. In electrocatalysis, electrode potential introduces an independently controllable energetic variable, but measured current–potential behavior also contains contributions from solution resistance, diffusion, migration, local pH, bubble dynamics, and electrolyte speciation. Electrolyte engineering therefore treats intrinsic electrolyte properties as quantitative design variables, particularly at non-extreme pH with buffered systems. Photocatalysis extends the same quantitative logic by adding photon absorption, carrier generation, separation, transport, and interfacial charge transfer before surface catalytic turnover. Once local kinetic, thermodynamic, and transport properties are independently established, multiphysics simulation can predict spatial distributions, product yield, and reactor performance. Electron chemical potential serves as a useful connecting energetic coordinate, while the central methodology is the quantitative decomposition of apparent catalytic performance into elementary kinetics and transport.