Issue 15, 2020

High pressure ammonia decomposition on Ru–K/CaO catalysts


Potassium-promoted ruthenium supported on CaO is a very efficient catalyst for ammonia decomposition, surpassing the performance of other Ru-supported solids. At an optimum Ru loading of 3% wt, catalysts with a K/Ru atomic ratio of 0.9 showed the best catalytic performance under a wide range of operating conditions, P = 1–40 bar, T = 250–550 °C and WHSV = 9000–30 000 mL g−1 h−1. Although NH3 conversion levels decrease considerably upon increasing the reaction pressure (X550 °C, 40 bar = 0.8), high pressure ammonia decomposition offers the possibility of COx-free compressed hydrogen and hydrogen productivities and TOFs 40 times bigger than when applying atmospheric pressure. Extensive characterization by CO chemisorption and HR-TEM demonstrates that potassium promotion increases metal dispersion by decreasing the Ru particle size. Electronic effects derived from the close proximity between K and Ru result in a decrease in the reaction apparent activation energy, as shown by a detailed kinetic analysis.

Graphical abstract: High pressure ammonia decomposition on Ru–K/CaO catalysts

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Article information

Article type
05 Apr 2020
26 Jun 2020
First published
29 Jun 2020
This article is Open Access
Creative Commons BY license

Catal. Sci. Technol., 2020,10, 5027-5035

High pressure ammonia decomposition on Ru–K/CaO catalysts

S. Sayas, N. Morlanés, S. P. Katikaneni, A. Harale, B. Solami and J. Gascon, Catal. Sci. Technol., 2020, 10, 5027 DOI: 10.1039/D0CY00686F

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