(513fn) Methods for the Analysis and Promotion of Electrocatalytic N2 Reduction | AIChE

(513fn) Methods for the Analysis and Promotion of Electrocatalytic N2 Reduction


Nielander, A. - Presenter, Stanford University
Jaramillo, T., Stanford University
Electrochemical N2 reduction (N2RR) has recently received significant interest as a renewably-powered, emissions-free alternative to the Haber-Bosch process and as a route to low temperature, low pressure NH3 synthesis. However, identifying catalysts and cell architectures that enable high activity and selectivity for N2 reduction to NH3 remains a significant challenge. The extent of this challenge is well demonstrated by a number of recent publications, including by our team of researchers, that describe methods and techniques for the evaluation of electrochemical N2 reduction. In this presentation, we critically examine recent advances toward improved methodologies for NH3 detection in N2RR-relevant electrolytes put forth by our team and others (including NMR, LC-MS, and colorimetric methods) and we discuss the advantages provided by each as well as our view of current best practices. We further discuss our efforts toward promotion and execution of reliable isotope-labeled 15N2 studies. We have recently described careful closed-loop gas recirculation and pressure/headspace management techniques using a custom-fabricated glass piston pump and 15N2 purification strategy. We compare our strategy to other methods, and we discuss the advantages and challenges associated with the use of closed-loop electrochemical reactors. With these methodologies in hand, we have continued our search for active N2RR catalysts and electrolyte conditions, and we discuss our most recent experimental and theoretical insights toward improving performance and understanding the mechanisms of this process.