Enhanced low temperature catalytic activity of Ni/Al–Ce0.8Zr0.2O2 for hydrogen production from ammonia decomposition

Ammonia decomposition is an effective way for high purity hydrogen production , yet the increase of catalytic activity at low temperatures remains a big challenge for this process. In this paper, a CeO 2 –ZrO 2 composite with Al as the secondary dopant was synthesized by the co-precipitation method, which was used as the carrier of nickel metal for ammonia decomposition. The experimental results showed that an obvious increase in catalytic activity of the ammonia decomposition at the relatively low temperature range of 450–550 °C was achieved over the nickel catalyst with CeO 2 –ZrO 2 composite as the metal carrier. Specifically, the complete decomposition of ammonia was achieved at 580 °C for Ni/Al–Ce 0.8 Zr 0.2 O 2 catalyst, while only 92% of ammonia was decomposed at 600 °C over the reference Ni/Al 2 O 3 catalyst. The characterization results indicated that the introduction of Al as the secondary dopant of ceria not only increases the specific surface area and oxygen defects on the surface, but also enhances the nickel metal dispersion and metal-support interaction, thus enhances the catalytic performance of Ni/Al–Ce 0.8 Zr 0.2 O 2 catalyst in the ammonia decomposition.