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 CeO2-ZrO2 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 degrees C was achieved over the nickel catalyst with CeO2-ZrO2 composite as the metal carrier. Specifically, the complete decomposition of ammonia was achieved at 580 degrees C for Ni/Al-Ce0.8Zr0.8O2 catalyst, while only 92% of ammonia was decomposed at 600 degrees C over the reference Ni/Al2O3 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-Ce0.8Zr0.8O2 catalyst in the ammonia decomposition. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.