Hydrogen production by ammonia decomposition over ruthenium supported on SiC catalyst

A series of ruthenium catalysts using beta-SiC as a support was synthesized with different metal loading (1-5 wt.% of Ru). Catalysts were characterized and tested with hydrogen production by catalytic ammonia decomposition. Additionally, the influence of calcination conditions as well as reduction temperatures (673 K and 873 K) was studied. Ru dispersion and metallic particle size were found to greatly influence catalytic activity. Moreover, calcination in a nitrogen atmosphere could remove a higher proportion of chlorine species derived from the precursor, thereby enhancing catalytic activity. Furthermore, a lower reduction temperature resulted in smaller particle sizes of ruthenium, which were more active in ammonia decomposition. Maximum intrinsic activity was obtained for a Ru size of around 5 nm. The catalyst containing 2.5 wt.% Ru, calcined in a N-2 atmosphere and reduced at 673 K resulted in excellent H-2 production from ammonia decomposition, with ammonia conversion close to 100% at 623 K was obtained. Porous SiC proved to be a suitable support for the nanosized Ru catalyst and was highly active in hydrogen production from ammonia decomposition. Moreover, this support provided good performance stability after one day of reaction. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

The study investigates the impact of catalyst preparation conditions on hydrogen production from ammonia decomposition. It is found that Ru dispersion and metallic particle size significantly affect catalytic activity. Calcination in a nitrogen atmosphere enhances catalytic activity, and lower reduction temperatures lead to more active ruthenium particles. Maximum intrinsic activity is achieved with Ru particle size around 5 nm under specific conditions.