Experimentally validated designs of two catalytic reactors, a Channel Gas-Phase reactor with photoelectrochemical enhancement(PE) and a Packed Bed Reactor is reported. Modeling studies involving kinetic and mass transfer parameters, surface reactions, the effect of light absorption on the reactions and reactor geometry, indicate that the reactors can be used for gas-phase heterogeneous oxidation reactions.

The Channel reactor is characterized in terms of the permeability and gas to solid mass transport. In the latter case, this is achieved by performing limiting current techniques using a liquid with the same Reynolds numbers as expected for the gas phase system. A mathematical model was developed to bring together the transport and mass transport behaviour of the reactor with the kinetics of the photocatalytic reactions as determined experimentally and the fluid flow behaviour enabling the simulation of the effect of temperature, concentration of contaminants, pressure, wavelength and light intensity on reactant conversion. The fluid flow distribution is modeled two dimensionally to allow the determination of fluid residence time distributions through the catalyst microstructure and any potential inactive zones.

The Channel reactor is optimized by varying the residence time, channel dimensions and the characteristics of the catalyst used including the thickness. A novel feature of the Channel reactor is the introduction of photo-electrochemical (PE) enhancement to suppress electron-hole recombination. This first attempt to carry out gas phase photo-electrochemical oxidation required the optimization of the electrode structure, thickness and ionomer content, achieved both by modeling the current distribution and experimentation. Results indicate that varying the structural parameters, measuring photocurrent and electrode response in a solid- state cell enabled the simulation of the actual PEC reactor.