【Haichuan Chemical Salary News】Zhang Lizhi and others from Central China Normal University have discovered a new method for ammonia synthesis at low temperatures, one that surpasses the Haber process!
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Zhang Lizhi et al. from Central China Normal University: A new method for ammonia synthesis that goes beyond the Haber process! Understanding Science 2020-04-08 20:35:15 The limitations of the Haber-Bosch reaction (especially when operated at high temperatures) have sparked new interest in low-temperature ammonia synthesis. N2 electroreduction is an attractive alternative, but due to the low ammonia production rate (mostly
First, a Ru/oxygen-doped Ru-core/shell nanocluster catalyst was designed for the electrocatalytic synthesis of ammonia. The room-temperature electroreduction of nitrates to ammonia catalyzed by this catalyst exhibits a high ammonia production rate (5.56 mol gcat-1 h-1), even higher than that of the Haber-Bosch process. It was found that oxygen doping causes the Ru unit cell to expand, thereby inducing tensile strain. The strained unit cell suppressed HER, but promoted the formation of ·H by eliminating the barrier of hydrogen-hydrogen coupling. Hydrogen radicals are the main contributors to this high catalytic performance, accelerating the conversion of nitrates to ammonia by hydrogenating the intermediates of the rate-determining step at a lower kinetic barrier. Due to the stable Ru-O surface coordination, at current densities > 120 mA cm-2, the strained nanostructure can maintain nearly 100% ammonia decomposition selectivity for 100 hours. Moreover, this strained nanocluster exhibits high selectivity over a wide range of applied potentials, and due to the strong bonding between Ru and the subsurface oxygen dopants, it shows excellent durability under high current levels.
If this discovery is true, even if it takes ten or twenty years before it can be put into industrial use, it will still represent a revolutionary breakthrough