Monday, 30 May 2022
West Ballroom B/C/D (Vancouver Convention Center)
Electrocatalytic CO2 reduction offers the potential of converting greenhouse gasses into usable products such as fuel and commodity chemicals. To achieve significant reaction efficiencies, the catalyst interface at the cathode must maximize catalyst utilization by providing uniform material distribution and maintain an adequate environment to promote CO2 reduction over the competing hydrogen evolution reaction. Spray deposition of the catalyst layer is a simple and economic technique that can provide uniform catalyst layers. This work evaluated the effect of catalyst ink composition on the deposition and performance of gas diffusion layer electrodes. Cu2Mo6S8 was used as the catalyst material, which has been shown to effectively reduce CO2 to formate and methanol in aqueous conditions. The ratio of water to isopropanol (10-40% volumetrically), type of binder (Polyethylene Glycol, Poly(acrylic acid), and Polytetrafluoroethylene) and binder content (25%, 50%, 75%) were all optimized to ensure effective and consistent mass transfer to the cathode electrode. It was found that ink using Poly(acrylic acid) as the binder with 25% binder content and 25% water, transferred mass the most efficiently, with an average efficiency of 57.4% ± 3.9%. The ink binder has shown to have an effect in the gas-liquid-solid three phase interphase, which is the reaction site for CO2 reduction. Consequently, the effect of the binder in the catalyst layer was evaluated in a CO2 flowthrough configuration using aqueous electrolyte. The liquid and gas products were analyzed through Nuclear Magnetic Resonance Spectroscopy and Gas Chromatography respectively.