Experimental Design for Accurate Reporting of Catalyst Activity in Nitrogen Reduction Experiments: Determination of the Optimal Membrane for Ammonia Retention

Abstract

Ammonia synthesis from dinitrogen provides a critical feedstock to agriculture worldwide. The dominant process for ammonia synthesis, Haber-Bosch, is fossil-fuel dependent, energy intensive, and highly centralized. Electrochemical nitrogen reduction (ENRR) could provide a decentralized and environmentally friendly route to ammonia synthesis. ENRR research is challenging due to low amounts of ammonia produced in a typical experiment relative to environmental levels. In the first part of this presentation, we will share a critical result in ENRR experimental design which significantly improves the retention of generated ammonia, specifically related to the selection of membrane separators for H-cell or gas diffusion electrode cell platforms. This result is applicable to both dinitrogen and nitrate reduction research. In the second part of this presentation, a VS2-based ENRR catalyst, which has experimentally shown promising activity and selectivity, will be presented. Additionally, the proposed mechanism of ENRR on VS2 will be discussed, and we will discuss density functional theory simulation of ENRR on VS2 and MoS2. Finally, we will address areas of opportunity for ENRR.