Layered Double Hydroxide-Derived Ni-Mg-Al Catalysts for Ammonia Decomposition Process: Synthesis and Characterization

Layered Ni-Mg-Al hydroxides with (Ni + Mg)/Al = 2.5 differing in Mg/Ni ratios and related oxide systems have been synthesized characterized. were prepared by the coprecipitation method. It was found that samples dried at 110 °C layered a hydrotalcite-type structure. After heat treatment 600 °C, formation of Ni-Mg-Al-mixed oxides specific nanostructure, an intermediate between NaCl spinel structure, took place. According to XRD data, it had unit cell parameter 4.174–4.181 Å, crystallite size 4.0 nm. The surface area 45–54 m2/g, those calcined 156.1–209.1 m2/g. In agreement HRTEM all nickel catalysts reduced 700 (H2), particle mainly distributed 15–20 catalyst activity LDH-derived ammonia decomposition studied fixed-bed flow-type reactor atmospheric pressure within temperature range 500–700 °C. overcame existing analogues catalytic performance. At process 500 Ni2Mg3Al2-HT showed H2 productivity 23.8 mmol/(gcat·min), exceeding respective value reported literature.