Novel exsolution catalysts for electrochemical ammonia synthesis using proton conducting cells – NEXT PCC

• Applicant: Dr. Moritz Kindelmann
• Subject Area: Synthesis and Properties of Functional Materials ; Glass, Ceramics and Derived Composites
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 548205046

Ammonia (NH3) plays a crucial role in global food production through its application in fertilizer synthesis. However, the current method of NH3 production via the energy-intensive Haber Bosch process results in significant CO2 emissions and natural gas consumption. There is an urgent need for the defossilization of the ammonia synthesis to reach targeted CO2 reduction goals and to change the production of ammonia to a process that is based on renewables as the energy source. The direct electrochemical synthesis of NH3 using solid oxide cells is a promising route to achieve these targets. Solid oxide cells based on proton conducting ceramics are of high interest, because they are able to combine the oxygen evolution reaction (production of mobile protons) and the nitrogen reduction reaction in one device. First developments have been promising, but the faradaic efficiencies and NH3 synthesis rates of proton conducting cells (PCCs) remain insufficient for industrial applications. In the proposed research project, we will investigate metal exsolution as a novel methodology to synthesize highly active catalyst nanoparticles (NP) for the electrochemical synthesis of NH3. Metal exsolution is a promising process for the synthesis of metallic nanoparticles through targeted reduction treatments of metal oxides. The perovskite ceramic BaZr0.5-xCe0.2Fe0.2RuxY0.1O3-delta (BZCFRuY) will be applied as the exsolution active host material, enabling the direct exsolution of FeRu nanoparticles to the perovskite surface. The project will investigate the fundamental kinetics of formation as well as the stability of FeRu under application atmospheres. Next to ex situ investigations using atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy, we will apply state of the art in situ transmission electron microscopy to understand the morphology and composition of exsolved FeRu NPs directly after formation. Furthermore, BZCFRuY exsolution electrode layers will be developed and integrated into the proton conducting cell architecture at DTU Energy to benchmark the electrochemical performance against different state of the art catalysts. The proposed project will produce novel fundamental insights into the formation and stability of bimetallic exsolution catalysts as well as investigate their performance for the direct electrochemical synthesis of ammonia.

• DFG Programme: WBP Fellowship
• International Connection: Denmark
• Hosts: Professor Dr. Søren Bredmose Simonsen; Professor Dr. Wolff-Ragnar Kiebach; Professor Dr. Peter Vang Hendriken