(532ef) Development of Novel Catalyst for Ammonia Oxidative Decomposition

Hydrogen is one of the most promising energy sources for the carbon-neutral society, which is the goal of the Paris Agreement. Hydrogen has the advantage of being able to store energy 4 times better than gasoline and 3 times better than natural gas. However, due to the low energy density per volume, there are difficulties in large-capacity storage and long-distance transportation. So hydrogen carriers, which are methods of efficiently storing hydrogen, are being actively studied.

Among them, ammonia is very eco-friendly, producing only hydrogen and nitrogen after the dehydrogenation reaction, and the hydrogen density per volume is much larger than that of liquefied hydrogen or LOHC, and can be easily liquefied at room temperature. However, there is a disadvantage in that a high temperature is required to cause a dehydrogenation reaction of ammonia, and a new reaction system using the oxidation reaction of ammonia and the acid adsorption heat of ammonia has been recently proposed to solve the disadvantage. In this reaction system, the heat generated from ammonia adsorption and the heat generated from the ammonia oxidation is used to supply the heat required for the ammonia decomposition.

However, the catalyst in the system developed so far still uses expensive Ru metal, and the disadvantage is that 33% of ammonia fed to reactor is consumed for the combustion, so that only 67% of ammonia is consumed for producing hydrogen. Therefore, this study developed a new type of bimetal catalyst that can lower the price of the catalyst increasing the low-temperature activity of the ammonia decomposition reaction. In addition, the form and characteristics of the catalyst were identified through TEM, TPD, and XRD, and the low-temperature activity of the ammonia oxidation and the acid sites for reaction system were improved.