![\"Pentametallic](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2026\/05\/547366_indexpentametallic_nanoparticle_synthesis_science7copy_909946.jpg\")
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A counterintuitive technique developed by researchers in the US and South Korea allows pentametallic nanoparticles of relatively uniform size and composition to form spontaneously from a precursor solution containing the five metals. The nanoparticles are a promising catalyst for the decomposition of ammonia into hydrogen and the technique could also potentially be extended to produce other multimetallic nanoparticles.<\/p>\n
Multimetallic nanocrystals can sometimes offer catalytic properties that nanocrystals of a single metal cannot such as higher atom economy for a precious metal or synergistic interactions between the metals. However, they can be difficult to synthesise because different reactivities or natural crystal structures of the constituent metals may not lead to compositionally uniform products. Most work to date has focused on energy-intensive schemes in which mixtures of the metals are cooled from very high temperatures in milliseconds or even microseconds to kinetically trap them, preventing the metals from forming separate phases.<\/p>\n
In the new work, researchers in the groups of Matte<\/a>o<\/a> Cargnello<\/a> at Stanford University in California and Hee-Tae Jung<\/a> at Korea Advanced Institute of Science and Technology took a subtler approach, depositing the metals from solution onto ruthenium nanoparticle seeds by mixing them with metal acetylacetonate precursor solutions and heating the mixture. When they studied bimetallic compositions, they found differing results. Iron formed variably sized, self-nucleated nanoparticles separate from ruthenium, copper formed core\u2013shell nanoparticles, and cobalt and nickel both formed mixtures of the two.<\/p>\n When the researchers added more metals together, however, they found that \u2013 instead of producing the expected morass of products \u2013 the distribution became more uniform. When they added precursors of all five metals, they found that they could reliably obtain RuFeCoNiCu particles about 20\u201325nm in size with constant atomic composition. Time lapse investigations indicated that the copper deposited first onto the ruthenium before other metals deposited onto the bimetellic nanoparticle. \u2018We think ruthenium has more affinity and miscibility with the cobalt, and copper has more affinity and miscibility with the nickel,\u2019 explains Cargnello. \u2018The fact that you have already deposited both copper and ruthenium on the same nanocrystal gives you the right conditions to deposit both nickel and cobalt on the same nanocrystal, rather than forming more mixtures in solution, and it\u2019s the same for the iron.\u2019<\/p>\n At a temperature of 900\u00b0C, the multimetallic catalyst could achieve a catalytic rate four times as high as ruthenium alone for the decomposition of ammonia. Its effectiveness was not optimal under conditions that favoured ammonia synthesis, but the research was financially supported by BASF\u2019s California Research Al<\/a>l<\/a>iance Program<\/a> looking at its potential in a hydrogen economy.<\/p>\n![\"Scheme\"](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2026\/05\/547365_pentametallic_nanoparticle_synthesis_science7_418543.jpg\")
<\/p>\n![\"Scheme\"](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2026\/05\/547364_pentametallic_nanoparticle_synthesis_science1_781893.jpg\")
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