Juliette Verschoor

Metal hydride nanocomposite materials as TM-free catalysts for ammonia synthesis

Ammonia is a well-known and vital part in the production of artificial fertilizers, but recently also acknowledged as a promising hydrogen carrier for the growing renewable energy infrastructure.^1,2 Unfortunately, the strong triple covalent bond in N₂ combined with high kinetic barriers results in high energy input demand.³ Nowadays, ammonia synthesis is still conducted using fused iron catalysts (Haber-Bosch) or alkali promoted ruthenium catalysts (Kellogg), which require very high temperatures and pressures (400-500°C, 10-30MPa), resulting in these processes amounting to 1-2% of the global energy consumption.¹

Alternative catalysts for ammonia synthesis have been emerging, including the use of hydrides, amides and electrides as an alternative to the Haber Bosch process.⁴ The aim of this project is to develop novel metal hydride based catalysts for ammonia synthesis at moderate temperatures and pressures (<400°C, 1MPa). Starting from alkali metal hydrides, specifically KH confined in graphitic carbon⁵, we are working towards highly active catalysts for ammonia synthesis and understanding the mechanism thereof. To achieve this, various types of (carbon) supports will be combined with different metal hydrides (LiH, NaH, KH) and investigated in detail. Moreover, long-term catalytic tests will be conducted under different conditions to evaluate catalyst activity and determine the optimal operation window.

This research is part of the EU AMBHER (Ammonia and MOF based Hydrogen for Europe) consortium, which focusses on tackling the short and long-term energy storage challenges.

1.        Guo, J. & Chen, P. Catalyst: NH3 as an Energy Carrier. Chem 3, 709–712 (2017).

2.        Makepeace, J. W. et al. Reversible ammonia-based and liquid organic hydrogen carriers for high-density hydrogen storage: Recent progress. Int. J. Hydrogen Energy 44, 7746–7767 (2019).

3.        Gao, W. et al. Production of ammonia via a chemical looping process based on metal imides as nitrogen carriers. Nat. Energy 2018 312 3, 1067–1075 (2018).

4.        Humphreys, J., Lan, R. & Tao, S. Development and Recent Progress on Ammonia Synthesis Catalysts for Haber–Bosch Process. Adv. Energy Sustain. Res. 2, 2000043 (2021).

5.        Chang, F. et al. Potassium hydride-intercalated graphite as an efficient heterogeneous catalyst for ammonia synthesis. Nat. Catal. 5, 222–230 (2022).

C.V.

2022 – present

PhD candidate in the Materials Chemistry and Catalysis group, Utrecht University, The Netherlands, on metal hydride nanocomposite materials for ammonia synthesis under supervision of Prof. Dr. Petra de Jongh and Dr. Peter Ngene.

2019 – 2021

Master’s degree in Nanomaterials Science, Utrecht University, The Netherlands.

Master thesis in the Materials Chemistry and Catalysis group at Utrecht University: “Carbon functionalization and its effects on carbon-supported nickel catalysts for CO₂ hydrogenation” under supervision of Nienke Visser, MSc and Prof. Petra de Jongh.

Master internship: “Development of stable electrocatalysts for seawater electrolysis”  in the group of Prof. Gadi Rothenberg at the University of Amsterdam.

2016 – 2019

Bachelor’s degree in Chemistry, Utrecht University, The Netherlands.         

Bachelor thesis: “Photo-degradation of apolar plastics in aquatic environment” under supervision of Iris ten Have, MSc and Dr. Florian Meirer in the Inorganic Chemistry and Catalysis group at Utrecht University, The Netherlands.

2010 – 2016

Secondary education at the Erasmiaans Gymnasium Rotterdam, The Netherlands.

1998

Born in Capelle aan den IJssel, The Netherlands.