We investigated various process conditions to observe how these parameters affect the observed kinetics. We expected that the gas flowrate should influence the mixing and mass transfer due to the hydrodynamics of a RS-SDR ; therefore, we used varying gas-to-liquid flow ratios to discern the effects of lower relative gas flows. As the results illustrate in Fig , the flow ratio is an important factor not only for the yield, but also for the selectivity. This is likely due to the enhanced mass transfer with an increase in relative gas velocities, as was demonstrated in the work of Meeuwse et al. . However, there are limits due to the solubility of oxygen in our solvent, and therefore, it seems as we go from a 2:1 ratio to a 3:1 ratio, this effect on the kinetics, becomes less pronounced. For a low gas flow ratio as is the case for a 1:1 ratio, we are also at a flow ratio below the stoichiometric requirement for the reaction. Therefore, this will also kinetically limit our reaction and possibly promote side reactions due to the unavailability of oxygen. already fixed for the system, we investigated if increasing the catalyst concentration could further enhance the productivity by improving the kinetics. In a system with RB as catalyst, the decay of the transmittance of light is an important factor (Supporting Information).