(544gy) Electrode Engineering: Modifying the Hydrophilicity of Carbon Paper for Improved Cobalt Phosphide Hydrogen Evolution Catalysts
AIChE Annual Meeting
Wednesday, October 31, 2018 - 3:30pm to 5:00pm
Various strategies including electrodeposition, nanoparticle synthesis, vapor phase phosphidations, and many others have been employed towards increasing the intrinsic activities and surface areas of MxPx but can be difficult and expensive to produce. In this work, we design and synthesize highly active CoP electrodes for the HER by tuning the hydrophobic and hydrophilic properties of the carbon support used during electrodeposition. Utilizing various oxidation methods, both physical and chemical, the surface O:C ratio is varied and is directly correlated to heterogeneity of cobalt phosphide deposition onto the surface of the carbon electrode. The degree of different oxygen-containing surface groups on carbon is tracked as a function of oxidation method and the most active electrode with a mass activity of >100 and >800 A/g at Î·=50 mV and 100 mV, respectively, which are among the highest shown in literature are correlated to a high concentration of carboxyl and hydroxyl functional groups on the surface as shown by X-ray photoelectron spectroscopy. Ultimately, we report a facile and translatable strategy to lower catalyst loading while maintaining extremely high mass activities on a 3D electrode.