Continuous photochemical conversion of CO2 to methanol in an optofluidic microreactor

Among the different alternatives to reduce CO2 emissions, Carbon Capture and Utilization (CCU) is particularly an interesting approach since it allows to reduce the reliance on fossil fuels and produce, at the same time, value added chemicals. This study shows how the photocatalytic reduction of CO2 may represent a suitable technology for tackling the CO2 challenge. By using an optofluidic microcell and TiO2 and Cu2O/TIO2 as photoactive surfaces, is possible to continuously convert CO2 to methanol with a maximum production rate and apparent quantum yield under UV irradiation of r= 2.23x10-6 MeOH mol/cm2h and AQY= 9.29% at 125 μl/min, 1mg/cm2 and at 86 W/m2 of flowrate, catalytic load and irradiance, respectively for a Cu2O-based photoactive surface. The optofluidic microreactor reported in this study has shown some advantages from previous designs, such as fine flow control, large surface-area-to-volume ratio and enhancement of mass transfer and microreactor illumination. The research efforts carried out are a step forward into the development of innovative processes for the continuous CO2-to-methanol reaction.Grado en Ingeniería Químic