Layered Double Hydroxide Derived Mg2Al-LDO Supported and K-Modified Ru Catalyst for Hydrogen Production via Ammonia Decomposition

Mg–Al mixed oxide is derived via the precursor of Mg 2 Al-layered double hydroxide (Mg 2 Al-LDH), and employed to load Ru and KNO 3 to develop the K–Ru/Mg 2 Al-LDO catalyst for hydrogen production through ammonia decomposition. Single MgO and Al 2 O 3 were used to prepare reference catalysts K–Ru/MgO and K–Ru/Al 2 O 3 for comparison. A mechanically mixed K–Ru/MgO and K–Ru/Al 2 O 3 sample was also made to explore the interaction of oxide constituents. K–Ru/Mg 2 Al-LDO generally outperforms K–Ru/MgO and K–Ru/Al 2 O 3 as well as the Ru-based catalysts supported on other transition metal oxides. The comparison study demonstrated significant impact of structural homogeneity and strong interaction of the oxide constituents on activity. The unique structural feature of Mg 2 Al-LDO gives rise to the enhanced surface basicity, low-temperature feasible N 2 desorption, and remarkable hydrogen spillover effect. All these aspects are favorable on K–Ru/Mg 2 Al-LDO for electronic modification of Ru sites, rate-determining steps in both low and high reaction temperature, and quick recycle of active sites, accounting for its superior activity plus good durability. Graphical Abstract