Innovative catalysts: An expert review
With the help of innovative elctrocatalytic materials, water can be split up into oxygen and hydrogen. Hydrogen is a fuel storing chemical energy as long as needed. © Dr. Ziliang Chen
Highly efficient (electro-)catalysts are essential for the production of green hydrogen, the chemical industry, fertiliser production and other sectors of the economy. In addition to transition metals, a variety of other metallic or non-metallic elements have now moved into the focus of research. In a review article, experts from CatLab and Technische Universität Berlin present an overview on current knowledge and a perspective on future research questions.
Green hydrogen is an important component in a climate-neutral energy system. It is produced by electrolytically splitting water with wind or solar power and stores this energy in chemical form. But currently, the production of green hydrogen is not yet economical or efficient enough. The key to solving this problem is through the development of innovative electrocatalysts, which should not only work with high efficiencies but should also be available and inexpensive.
In addition to transition metals, which are already well studied for their catalytic properties, a wider choice of elements has now moved into the focus such as alkali metals, alkaline earth metals, rare earth metals, lean metals and metalloids. Some of these when combined with transition metal electrocatalysts can significantly improve performance and contribute to the development of next-generation high-performance electrocatalysts.
However, many of the processes that take place during electrocatalysis -when oxygen or hydrogen is formed - are still not understood in detail. In a review article, an international team of experts guides us through this exciting research field and draws a perspective, sketching the next steps catalyst research could take. “This contribution summarises the current state of knowledge on such unconventional s-, p-, and f-block metal-based materials and makes it comprehensible to a wider community of scientists”, Dr. Prashanth W. Menezes points out and adds: "Further, the essential role of such metals during water splitting electrocatalysis is described in great depth, as well as the modification strategy that should be considered when one wants to utilize them to mediate non-noble-based electrocatalysts. We hope to significantly accelerate research and development of novel, innovative catalyst materials with this review article."
Note: Dr. Prashanth W. Menezes is Head of Materials Chemistry for Thin-Film Catalysis Group in the CatLab-Project at HZB and Head of Inorganic Materials Group at TU Berlin.
His twitterhandle is @EnergycatLab
CatLab: Together with the Fritz Haber Institute of the Max Planck Society, HZB is setting up the Catalysis Laboratory CatLab, which is intended to accelerate research into innovative catalysts. CatLab is supported by the German Federal Ministry of Education and Research.
- Battery research: visualisation of aging processes operandoLithium button cells with electrodes made of nickel-manganese-cobalt oxides (NMC) are very powerful. Unfortunately, their capacity decreases over time. Now, for the first time, a team has used a non-destructive method to observe how the elemental composition of the individual layers in a button cell changes during charging cycles. The study, now published in the journal Small, involved teams from the Physikalisch-Technische Bundesanstalt (PTB), the University of Münster, researchers from the SyncLab research group at HZB and the BLiX laboratory at the Technical University of Berlin. Measurements were carried out in the BLiX laboratory and at the BESSY II synchrotron radiation source.
- New instrument at BESSY II: The OÆSE endstation in EMILA new instrument is now available at BESSY II for investigating catalyst materials, battery electrodes and other energy devices under operating conditions: the Operando Absorption and Emission Spectroscopy on EMIL (OÆSE) endstation in the Energy Materials In-situ Laboratory Berlin (EMIL). A team led by Raul Garcia-Diez and Marcus Bär showcases the instrument’s capabilities via a proof-of-concept study on electrodeposited copper.
- Green hydrogen: A cage structured material transforms into a performant catalystClathrates are characterised by a complex cage structure that provides space for guest ions too. Now, for the first time, a team has investigated the suitability of clathrates as catalysts for electrolytic hydrogen production with impressive results: the clathrate sample was even more efficient and robust than currently used nickel-based catalysts. They also found a reason for this enhanced performance. Measurements at BESSY II showed that the clathrates undergo structural changes during the catalytic reaction: the three-dimensional cage structure decays into ultra-thin nanosheets that allow maximum contact with active catalytic centres. The study has been published in the journal ‘Angewandte Chemie’.