Highly Efficient Ru/MgO Catalyst with Surface-Enriched Basic Sites for Production of Hydrogen from Ammonia Decomposition

Development of highly active and stable catalyst for decomposition of ammonia to COx-free hydrogen is an urgent and challenging task. Here, MgO (c-MgO) supported Ru nanoparticles derived from Ru/4MgCO(3) center dot Mg(OH)(2) center dot 4H(2)O composite was prepared by deposition precipitation method and investigated as catalyst for NH3 decomposition. The use of 4MgCO(3) center dot Mg(OH)(2) center dot 4H(2)O as support precursor leads to high density of basic sites and highly dispersed Ru nanoparticles (3.8-6.0 nm) on the Ru/c-MgO catalysts. Thus, the Ru/c-MgO catalysts show much enhanced activities and robust stability in the long-term run (over 100 hours). Characterization results reveal that the much enhanced dispersion of Ru nanoparticles, high density of surface base sites and strong interaction between Ru nanoparticles and c-MgO all benefit the highly efficient Ru/c-MgO catalysts in NH3 decomposition. Further improvements in activity can be achieved by modification of Ru/c-MgO catalyst with an optimized KOH content. Therefore, it is believed that the use of 4MgCO(3) center dot Mg(OH)(2) center dot 4H(2)O as support precursor opens opportunity to achieve highly active and stable Ru/MgO catalysts through tuning the basic properties of catalysts.