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Green ammonia, a \"zero-carbon\" fuel that produces only nitrogen and water when burned, is considered an ideal carrier for storing green hydrogen, and it is becoming a new focus in the energy transition. The team led by Professor Shen Xinghai from the School of Chemistry and Molecular Engineering at Peking University has cleverly utilized the special two-dimensional carbon material graphyne, in combination with depleted uranium – which is considered a waste material in the nuclear industry – to develop a completely new type of composite catalyst that can efficiently catalyze the synthesis of ammonia under mild conditions. The relevant findings were recently published in Nature Communications. To promote a low-carbon transformation of the energy system and achieve China’s \"dual carbon\" goals, the country has explicitly proposed a plan to use green ammonia as a substitute for coal, with 10% of the coal to be replaced by green ammonia. However, the key process for producing green ammonia is the century-old Haber-Bosch method, which requires high temperature and pressure; as a result, the cost of each ton of green ammonia is more than twice that of ammonia produced using fossil fuels. “Reducing the cost of green ammonia requires turning to a new generation of flexible processes, the key to which lies in the development of high-performance catalysts to enable the efficient thermocatalytic synthesis of ammonia under mild conditions. “Shen Xinghai told a reporter from Science and Technology Daily. Shen Xinghai’s team has been engaged in interdisciplinary research at the intersection of radiochemistry and other cutting-edge technologies; this time, the team developed a uranium-graphyne composite catalyst. Uranium atoms are dispersed on graphitene in the form of tiny clusters, with the distance between adjacent uranium atoms being exactly equal to that of a nitrogen molecule. This structure enables nitrogen molecules to be efficiently captured and activated in a \"bridged adsorption\" mode, laying a crucial foundation for subsequent hydrogenation reactions. Using supercritical carbon dioxide as the medium, the research team identified the optimal reaction conditions, successfully achieving the controlled synthesis of single-layer and few-layer graphyne. They also determined the patterns of change in its layer count and optical band gap, providing a scientific basis for the precise regulation of its catalytic properties. This new catalyst performs excellently: under mild conditions of 150°C and 15 atmospheres, it achieves an ammonia production rate of 587.5 micromoles per gram per hour, and it also exhibits good cycle stability. The team also found that the 5f electrons of uranium interact uniquely with the conjugated structure of acetylene, enabling more efficient recognition of nitrogen molecules, their conversion, and the release of the resulting ammonia molecules; thus, the catalytic process exhibits both high selectivity and high efficiency. Previously, research on uranium has mainly focused on the field of nuclear fuel, and the potential of its unique 5f electron orbitals in catalysis has been little explored. The research team’s findings suggest that depleted uranium, once considered a byproduct in the nuclear industry, has the potential to become a high-value catalyst material. Shen Xinghai said that this work has had a positive impact on the development of actinide chemistry as well as the field of new two-dimensional carbon materials ； It is also a successful exploration of the integration between radiochemistry and catalytic science; it has solved the key technical challenges in the development of the green ammonia industry, contributing to the creation of a \"new identity\" for green fuels and to the implementation of energy security strategies in the new era.