Adaptive Catalytic Systems
Chemical transformations with molecular hydrogen (H2) are fundamental pillars of the chemical industry and used across the entire value chain, ranging from the production of fuels, fine chemicals, agrochemicals, and pharmaceuticals. With the rise of alternative renewable energy sources and chemical feedstocks, the permanent evolution of novel hydrogen technologies is of ever increasing importance. Catalysts are essential to control the activation and transfer of hydrogen in particular for the selective conversion of biomass-derived substrates and intermediates.
In a world where flexibility is becoming increasingly important, the design and development of such catalysts whose reactivity can be changed at will or even self-adjusts during the process is of great interest, but remains a challenge.
In an article recently published in Nature Chemistry, an international team of scientists led by JARA-ENERGY scientist Prof. Walter Leitner, Chair of Technical Chemistry and Petrochemistry at RWTH Aachen University and Director at the Max Planck Institute for Chemical Energy Conversion, now reports a rationally designed catalyst that adapts fully reversibly and in real time to changes in the reaction system, enabling the selective generation of different products depending on the source of hydrogen.
While previously developed catalysts often demonstrate outstanding properties regarding their dedicated tasks, their performance is typically optimized to remain static. The development of an adaptive catalytic system whose reactivity is reversibly modified upon changes in the reactive environment is particularly difficult. To tackle this challenge, the research team combined expertise on nanoparticle-based catalysis and CO2-responsive materials. When used in hydrogenation reactions, which can result in different products, the new catalyst is able to “recognize” whether the feed gas is composed of pure hydrogen or is a mixture of hydrogen and carbon dioxide (CO2).
Depending only on the gas supply, it operates in two different modes, selectively producing two different products from the same starting material under otherwise identical conditions. It is possible to switch back and forth between the two modes of operation in almost real time.
The published study was supported, in particular, by RWTH’s The Fuel Science Center Cluster of Excellence, which has defined the development of adaptive catalytic systems as one of its main objectives. The authors hope that their proof of concept of an adaptive catalytic system for hydrogenation reactions will open up many new opportunities to develop other adaptive catalytic systems and enable flexible production schemes based on renewable feedstocks and energy supply.
Selectivity control in hydrogenation through adaptive catalysis using ruthenium nanoparticles on a CO2-responsive support. https://www.nature.com/articles/s41557-021-00735-w