# Laser-Induced Pd-PdO/rGO Catalysts for Enhanced Electrocatalytic Conversion of Nitrate into Ammonia

## TL;DR

A new laser-made catalyst converts nitrate to ammonia efficiently at low energy, offering a sustainable way to produce ammonia.

## Contribution

A novel Pd-PdO/rGO catalyst synthesized via a laser-assisted one-step method shows high ammonia yield and selectivity under ambient conditions.

## Key findings

- The Pd-PdO/rGO catalyst achieved a maximum ammonia yield of 5456.4 ± 453.4 μg/h/cm2 at −0.6 V vs RHE.
- At −0.1 V, the catalyst showed high ammonia selectivity (74.9 ± 4.4%) with minimal hydrogen evolution.
- The catalyst's activity and stability can be regenerated through electrooxidation of Pd.

## Abstract

Electrochemical reduction
of nitrate to ammonia (eNO3RR) is proposed as a sustainable
solution for high-rate ammonia synthesis
under ambient conditions. The complex, multistep eNO3RR
mechanism necessitates the use of a catalyst for the complete conversion
of nitrate to ammonia. Our research focuses on developing a novel
Pd-PdO doped in a reduced graphene oxide (rGO) composite catalyst
synthesized via a laser-assisted one-step technique. This catalyst
demonstrates dual functionality: palladium (Pd) boosts hydrogen adsorption,
while its oxide (PdO) demonstrates considerable nitrogen adsorption
affinity and exhibits a maximum ammonia yield of 5456.4 ± 453.4
μg/h/cm2 at −0.6 V vs reversible hydrogen
electrode (RHE), with significant yields for nitrite and hydroxylamine
under ambient conditions in a nitrate-containing alkaline electrolyte.
At a lower potential of −0.1 V, the catalyst exhibited a minimal
hydrogen evolution reaction of 3.1 ± 2.2% while achieving high
ammonia selectivity (74.9 ± 4.4%), with the balance for nitrite
and hydroxylamine. Additionally, the catalyst’s stability and
activity can be regenerated through the electrooxidation of Pd.