Enhanced Catalytic Ammonia Synthesis with Transformed BaO

We report that a simple mixture of BaO and CaH 2 powders with ruthenium nanoparticles acts as an effective heterogeneous catalyst for low-temperature ammonia synthesis with a very small activation energy (41 kJ mol –1 ). The high catalytic performance of this material is not due to either the original CaH 2 or BaO particles but to BaO transformed by reaction with CaH 2 . The transformed BaO contains BaH 2, a stable and strong electron-donating material that facilitates a reversible hydrogen storage-release reaction and significantly enhances electron donation to Ru, which results in high catalytic performance.