Affordable Green Hydrogen from Alkaline Water Electrolysis: Key Research Needs from an Industrial Perspective

Abstract

Hydrogen is poised to play a key role in the energy transition by decarbonizing hard-to-electrify sectors and enabling the storage, transport, and trade of renewable energy. Recent forecasts project a thousand-fold expansion of global water electrolysis capacity as early as 2030. In this context, several electrolysis technologies are likely to coexist in the market, each catering to different applications and geographies. They face the common challenge of decreasing the cost of hydrogen produced, for which energy efficiency is a major but not the only factor. In this Perspective, we dispel common misconceptionsrooted in outdated designsaround alkaline water electrolysis and offer an overview of the main technical pathways to reduce the cost of hydrogen from modern systems already under commercialization. By identifying key research needs, we aim to motivate work into overlooked areas that both offer interesting scientific questions and can contribute to the gigawatt-scale production of green hydrogen in the short- to medium-term.

Application of Ionized Intrinsic Microporous Poly(phenyl-alkane)s as Alkaline Ionomers for Anion Exchange Membrane Water Electrolyzers

“…The production of green hydrogen (H 2 ) via water electrolysis is attracting attention for its potential role and applicability in the large-scale utilization of renewable energy and decarbonization. − Among various water electrolysis technologies, the anion exchange membrane water electrolyzers (AEMWEs) combine the advantages of the low cost of alkaline water electrolyzers and the high efficiency of proton exchange membrane water electrolyzers. − Correspondingly, AEMWEs have shown great potential for commercialization . The membrane electrode assembly (MEA) is the basic unit of an AEMWE and is mainly composed of an anion exchange membrane (AEM), a catalyst layer (CL), and a gas diffusion layer (GDL). , The structural design and components of MEAs directly determine the H 2 output rate and cell efficiency of AEMWEs.…”

Photo-assisted electrochemical CO2 reduction at a boron-doped diamond cathode

“…15 This may help produce energy with a lower environmental impact, 16–18 as in the case of hydrogen production from water electrolysis. 19–22…”

“…15 This may help produce energy with a lower environmental impact, [16][17][18] as in the case of hydrogen production from water electrolysis. [19][20][21][22] In a (photo)electrochemical system, energy efficiency is affected by several energy losses, mainly ascribed to the electrochemical cell (e.g., ohmic drop, electrolyte, mass transport, and separators), 23,24 which can be reduced by a careful engineering design, and the overpotential that is intrinsic for the reaction and electrocatalyst/electrode materials used. In particular, when a reduction reaction is coupled with the oxygen evolution reaction (OER) from water oxidation, this 4-electron reaction may account for the largest loss of energy in the electrochemical system due to overpotential.…”

Metal deposition and electrocatalysis for elucidating structural changes of gold electrodes during cathodic corrosion

“…Electrochemical energy conversion systems, including alkaline water electrolysis for H 2 production, electroreduction of CO 2 (CO 2 RR) to hydrocarbons, N 2 reduction reaction (NRR), oxygen reduction reaction (ORR), and cathodic electro-conversion in organic electrosynthesis, and many more, are gaining momentum as a sustainable route for the production of "green" fuels and industrially relevant chemicals. [1][2][3][4][5][6][7][8][9][10][11][12] Indeed, the development of active, selective, and affordable electrocatalysts with high stability and long-term performance is the key element for the future progress and application of these electrochemistry-related technologies. 13,14 Typically, the aforementioned electrocatalytic reactions take place in the presence of alkali metal or organic cations at high cathodic current densities.…”