Modulated electronic environment of Ru on CeO2 for superior NH3 decomposition catalysis

초록

Ammonia has emerged as a promising, carbon-free carrier of hydrogen fuel, facilitating a sustainable energy transition. Ru-based catalysts have been widely employed to produce hydrogen via NH3 cracking catalysis, specifically for the Ru/CeO2 catalyst, which exhibits strong metal-support interactions between the active Ru metal and the ceria support. This study demonstrates the superior catalytic activity of Ru/CeO2 catalysts, supported by experimental evidence and theoretical validation. We focus more on how the metal-support interaction modulates the electronic state of Ru, thereby enhancing catalytic performance. Through systematic characterization of various supports, the electron transfer at the Ru-CeO2 interface enhances the electron density of Ru, thereby mechanistically influencing the initial NH3 activation and N-H dissociation. The theoretical calculation, performed using density functional theory, further confirms these observations: the electron back-donation effect of Ru, induced by the Ru-CeO2 interaction, lowers the ammonia activation barrier and increases the reaction rate. This work highlights the importance of an interfacial electronic state for designing superior ammonia decomposition catalysts.

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