Hydrogen production via catalytic decomposition of NH3 using promoted MgO-supported ruthenium catalysts

Catalytic decomposition of NH3 to high purity hydrogen offers a promising strategy for fuel cells, but presents challenges for high hydrogen yields at comparatively low temperatures due to the lack of efficient catalysts. Here, we report the facile preparation of ultra-fine ruthenium (Ru) species dispersed on MgO, which show excellent activity and high temperature stability for NH3 decomposition reaction. The hydrogen yield of the prepared Ru/MgO catalysts reaches ca. 2,092 mmol H-2 g(Ru)(-1) min(-1) at 450 degrees C, far exceeding that of the previously reported most reactive Ru-based catalysts and the same chemical composition samples prepared by other approaches. Various characterization techniques containing X-ray absorption fine structure (XAFS), in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRTFTS) and temperature-programmed reduction/desorption (TPR/TPD) were carried out to explore the structure-function relation of the prepared Ru/MgO catalysts. We found that the Ru species interact strongly with the MgO support, which can efficiently protect the Ru species and MgO support from agglomerating during NH3 decomposition test, maintaining the stability of the catalysts.