부산대학교 도서관

For the upscaling of the electrochemical conversion of CO2to CO using Ag catalyst in water, gas diffusion electrodes (GDE) are needed for a sufficient supply of CO2to obtain currents in the 100 mA cm−2range. The effects of an upscale of one order of magnitude starting with 10 cm2GDE size are presented. The penetration of electrolyte through the GDE needs to be regulated to balance the positive effects (avoid salt deposition) and the detrimental impacts (access blocking of CO2to the GDE). Using a control of the partial pressure at the GDE to monitor the electrolyte penetration and enhancing CO2feed by recirculation and turbulence promoters at the larger GDE. The first step of scale-up could be achieved without loss in performance. With three-compartment cells and 0.4 M K2SO4electrolytes, the process is run at a current density of 150 mA cm−2over a couple of hundred hours with a Faradaic efficiency for CO (FECO) of approximately 60% on 100 cm2electrode area. It is discussed how to improve the performance by a management of the perspiration rate through the GDE to lay the scientific foundations for an industrial use of this technology.