The increasing demand for energy carriers from sustainable sources drives the search for fossil fuel-free alternatives. Ammonia is a carbon-free energy carrier for molecular hydrogen and has significant practical benefits such as liquefaction under mild conditions and high volumetric energy density. NH3 has also been proposed as a medium for energy storage to directly power fuel cells. Realizing NH3 as a carbon-free alternative fuel requires the development of efficient catalytic conversion strategies between ammonia and molecular hydrogen in both directions. With a potential of +0.092 V (vs. NHE, pH=0) for ammonia oxidation (AO) in water, it is relatively mild in comparison to water oxidation.