Rational Design of Hydrogen Evolution Reaction Electrocatalysts for Commercial Alkaline Water Electrolysis

Abstract

With the further exploitation of renewable energy sources, electrochemical hydrogen evolution reaction (HER) is considered a key technology to solve environmental problems and achieve global carbon neutrality. Currently, alkaline water electrolyzers (AWEs) have been revitalized as a traditional electrolytic water production industry, yet they face great challenges in achieving new technological breakthroughs due to the catalytic properties of electrode materials. In alkaline media, besides the slow kinetics of oxygen evolution reaction, the sluggish HER needing water dissociation and the mass transfer problems at high current densities are among the major factors limiting the development of alkaline water electrolysis for industrial applications. Therefore, it is of great importance to design HER electrocatalysts with high activity and stability at high current densities (>500 mA cm−2) for industrial applications at the “Research and Development level” (R&D level). Herein, a brief overview of the development of AWEs at the industrial scale is presented, and some mainstream recognized catalysis mechanisms for HER in alkaline electrolytes are summarized. Based on the requirements of industrial application and theoretical guidance, the activation strategies of HER electrocatalysts are also summarized. This review will propose new insights into the future development of alkaline water electrolysis.

Aminosilanized Interface Promotes Electrochemically Stable Carbon Nitride Films with Fewer Trap States on FTO for (Photo)electrochemical Systems

“…We propose that the limitation in FE H2 we observe at much lower current densities can be related to the hydrogen bubble generation and detachment. The enlarging hydrogen bubbles which do not detach can induce the local inhibition of the mass transfer at the surfaces . Permeation of the electrolyte can also cause mass transfer issues beneath the CN x surface.…”

Electrodeposited Multimetal Alloyed NiMoCo on Ni Mesh for Efficient Alkaline Hydrogen Evolution Reaction

“…Hydrogen is an important clean energy source that solves the energy crisis and achieves decarbonization. − Alkaline water electrolysis (AWE) hydrogen production is one of the most mature and widely used hydrogen production technologies in the industry today. , Although AWE has encountered new opportunities in today’s society for green hydrogen production, it still needs high operating cell voltages along with high electricity energy input. The development of industrial-scale electrocatalysts suitable for industrial applications is of great significance to extend the service life of AWE and reduce preparation, operation, and postmaintenance costs . Currently, the commercially used electrocatalyst is a nickel–aluminum alloy (NiAl alloy, Raney Ni) sprayed on a porous Ni mesh.…”

“…Currently, the commercially used electrocatalyst is a nickel–aluminum alloy (NiAl alloy, Raney Ni) sprayed on a porous Ni mesh. This NiAl alloy can operate steadily for tens of thousands of hours at high current densities, even at high alkali concentration (6 M KOH), high operating temperature (60–80 °C), and high pressure (2–10 bar), but its poor catalytic activity and large overpotential result in high costs for hydrogen production. − …”

“…The development of industrial-scale electrocatalysts suitable for industrial applications is of great significance to extend the service life of AWE and reduce preparation, operation, and postmaintenance costs. 7 Currently, the commercially used electrocatalyst is a nickel−aluminum alloy (NiAl alloy, Raney Ni) sprayed on a porous Ni mesh. This NiAl alloy can operate steadily for tens of thousands of hours at high current densities, even at high alkali concentration (6 M KOH), high operating temperature (60−80 °C), and high pressure (2−10 bar), but its poor catalytic activity and large overpotential result in high costs for hydrogen production.…”

Construction of a ruthenium-doped CoFe-layered double hydroxide as a bifunctional electrocatalyst for overall water splitting

“…10 Meanwhile, research has demonstrated that Ru-doped LDH also holds an outstanding absorption capability with hydrogen intermediates, 11,12 which is promising to catalyse the HER efficiently by decreasing the kinetic energy barrier of the Volmer step in the HER. 13 Nevertheless, there is still large room for electrolysis catalysts in industrial hydrogen production. More recently, efforts have been invested in catalysing the reaction under more practical conditions ( e.g.…”