To overcome this issue, we turned our attention to the use of porous material, which is widely used for exhaust gas treatment in automobiles . A porous device can improve the gas contact efficiency in exhaust gas treatment. Cataler has developed gas-liquid mixing technology using a honeycomb reactor made of porous material (Figure ) . Narrow channels separated by porous walls allow for high density accumulation in the reactor. When the gas-liquid reaction mixture passes through the honeycomb reactor, the porous material will function as a static mixer, and a high mixing efficiency can be maintained throughout the aerobic oxidation. We believe that this processing technology offers much potential for application as a flow reactor with a highly efficient and reliable static mixer in its full range. Such a reactor should become one of the ideal devices for aerobic oxidation under continuous flow conditions. Herein, we describe the feasibility of the honeycomb reactor for aerobic oxidation.