Efficient Electrochemical Methods for Low-Loading Ru Deposition on Carbon Electrodes as a Hydrogen Evolution Reaction Catalyst in an Acidic Environment

The widespread development of technologies for green hydrogen production strictly relies on the availability of durable electrocatalysts that can operate in either acidic or alkaline electrolytes while using a limited amount of platinum group metals. In this work, we present an effective strategy based on electrodeposition as a low-cost method to obtain low-loading Ru catalysts on carbon electrodes for the hydrogen evolution reaction in an acidic environment. The deposition conditions have been investigated and optimized in order to have uniform coverage, a large number of active sites, and good electrocatalytic performance. The morphology and chemical structure have been investigated using scanning electron microscopy and X-ray photoelectron spectroscopy measurements. Excellent catalytic activity has been achieved with a Ru loading of 0.06 mg cm^-2, obtaining an overpotential of 67 mV at 10 mA cm^-2 and a Tafel slope of 50 mV dec^-1.