# Continuous Ammonia Electrosynthesis from Nitrogen and Water in a Monolithic Pd Membrane-Based Flow Cell

## TL;DR

A new method for continuously producing ammonia using electricity, nitrogen, and water with a palladium membrane achieves improved efficiency.

## Contribution

A novel flow-cell design using a Pd membrane for proton transport enhances ammonia electrosynthesis efficiency.

## Key findings

- A Faradaic efficiency of 36 ± 4% was achieved at −6 mA cm–2 over 6 hours.
- Online mass spectrometry confirmed protons from water oxidation were used in ammonia production.
- The Pd membrane enabled continuous operation in a nonaqueous system.

## Abstract

Continuous electrochemical
lithium-mediated ammonia production
has shown promising performance. For this reaction, water oxidation
could provide a direct route for proton supply, eliminating the need
to generate molecular hydrogen. However, recent studies have reported
low Faradaic efficiency for ammonia when water is used directly as
the proton source. In this work, we integrate an electrically isolated
Pd membrane to transfer protons generated from water oxidation into
a nonaqueous lithium-mediated nitrogen reduction system. By employing
Pd as a proton- and electron-conducting membrane rather than solely
as a cathode, we enabled continuous operation in a flow-cell configuration,
achieving a Faradaic efficiency of 36 ± 4% at a current density
of −6 mA cm–2 over 6 h. Online mass spectrometry
confirmed that the produced ammonia contained protons generated by
water oxidation. This approach to using Pd provides a practical strategy
for proton transport and establishes a viable device configuration
to advance electrochemical lithium-mediated nitrogen reduction toward
sustainable green ammonia synthesis.