Storage and dissemination of clean energy from a renewable feedstock is one of the biggest challenges facing humanity. Electrocatalytic water splitting is an attractive scheme for the production of H2 as a carbon-neutral fuel and feedstock chemical that can be generated from renewable sources such as solar, wind, or geothermal. Electrocatalytic water splitting uses electrical energy generated from a renewable external source, such as solar, to split water (H2O) into hydrogen (H2—produced via proton reduction) and oxygen (O2—produced via water oxidation). The produced H2 can then be collected and used as a clean, carbon-neutral fuel, or feedstock for other commodity chemical production such as N2 hydrogenation to ammonia.
Current state-of-the-art electrolyzers consist of alkaline electrolysis (AEL) using a diaphragm to separate the electrodes, proton-exchange polymer electrolyte membrane electrolysis (PEMEL) in neutral or acidic media, and alkaline anion exchange membrane electrolysis (AEMEL). While AEL is a mature technology, it is limited by the purity of the gases produced and the pressure at which it can produce H2. On the other hand, PEMEL uses an ionically conducting membrane to separate the anodic and cathodic chambers, allowing a much more pure and higher pressure of H2 produced. However, PEMEL suffers from the use of noble metal catalysts, such as IrOx and IrRuOx for the oxygen evolution reaction (OER), while other earth-abundant catalysts based on Co, Ni, and Fe are unstable in the acidic conditions for PEMEL. AEMEL, on the other hand, can operate with earth-abundant catalyst, but are limited by the overpotential required for higher current density, creating larger power loss for the system.
Green hydrogen, i.e. hydrogen produced from the electrolysis of water, is a carbon-neutral fuel that can be generated using renewable energy and disseminated widely, thereby decarbonizing the global economy and creating the conditions for a sustainable future in Europe and the world. The RENEW project has synthesized new, highly performing, inexpensive OER catalysts for the production of green hydrogen. These catalysts outperform the state-of-the-art and are less expensive to synthesize. Thus, we as a society are closer towards a sustainable future, and opens the door towards scientific and economic opportunities to be exploited from these developments.
This project, Renewable Energy through New Electrolysis catalysts for Water splitting (RENEW), specifically aimed to examine novel electrode/catalyst materials and architectures to improve intrinsic catalyst activity and stability for use in water electrolysis. The specific objectives of RENEW were the following:
Objective 1: Fabrication, Activity and Stability of new Electrode/Catalysts based on Earth Abundant Metals.
Objective 2: Development of Nanostructured Electrode/Catalyst Assemblies.
