Insights into the High Activity of Ruthenium Phosphide for the Production of Hydrogen in Proton Exchange Membrane Water Electrolyzers

Abstract

The demand of green hydrogen, that is, the hydrogen produced from water electrolysis, is expected to increase dramatically in the coming years. State‐of‐the‐art proton exchange membrane water electrolysis (PEMWE) uses high loadings of platinum group metals, such as Pt in the electrode where hydrogen is produced. Alternative electrodes based on phosphides, sulfides, nitrides, and other low‐cost alternatives are under investigation. Herein, a simple process for the preparation of RuP electrodes with high activity for the hydrogen evolution reaction (HER) in acidic electrolyte is described. A straightforward one‐pot synthesis that yields RuP nanoparticles with fine‐tuned composition and stoichiometry is presented, as determined by multiple characterization techniques, including lab‐ and synchrotron‐based experiments and theoretical modeling. The RuP nanoparticles exhibit a high activity of 10 mA cm−2 at 36 mV overpotential and a Tafel slope of 30 mV dec−1, which is comparable to Pt/C. Moreover, a RuP catalyst‐coated membrane (CCM) with a low Ru loading of 0.6 mgRu cm−2 is produced and tested in a PEMWE cell configuration, yielding 1.7 A cm−2 at 2 V.

Precious Metal Free Hydrogen Evolution Catalyst Design and Application

“…Tafel slope analysis should always be contextualized with other activity and kinetics metrices including TOF, exchange current densities, ECSA and other measurements that help articulate reaction mechanisms and reaction kinetics. If used on their own, Tafel slopes become ambiguous and often lead to erroneous conclusions. , For example, symmetry factors must be used to effectively correct Tafel slopes, but accurately assigning the symmetry factor is inherently challenging. Thus, it is important to contextualize Tafel slope discussions to methods used and other kinetics parameters.…”

“…Their method also enables an extraction of transfer coefficients, rate constants, and hydrogen coverages. An example of the synergy between Tafel analysis and EIS is presented by Galyamin et al, where they show direct correlation between the Tafel slopes determined from voltametric techniques and the equivalent circuit elements from the EIS analysis . Such cross-examining approaches are highly encouraged to find methodologies that can be universally adopted across various families of electrocatalysts.…”

A Comparative Analysis of Different Hydrogen Production Methods and Their Environmental Impact

“…PEM electrolysers, another type of electrolysis device, are used for the production of hydrogen gas [30]. These electrolysers deploy a proton exchange membrane as the electrolyte, an example being NafionTM.…”

Unraveling the Most Relevant Features for the Design of Iridium Mixed Oxides with High Activity and Durability for the Oxygen Evolution Reaction in Acidic Media

“…This approach not only allows for the determination of C dl but also accounts for the nature of the surface roughness . Furthermore, if required, EIS facilitates conducting more comprehensive studies, enabling the investigation of the physicochemical properties of the material at the nanoscale, similar to those examined in supercapacitors. , Moreover, measuring the CPE by EIS allows us to study the surface reconstructions and to determine the evolution of the surface area during the OER cycles (see an example in SI Figure S3).…”