Ceria-reduced graphene oxide nanocomposite as an efficient electrocatalyst towards artificial N2 conversion to NH3 under ambient conditions

Abstract

For over a century, NH₃ synthesis via the Haber–Bosch process has brought huge energy costs and high CO₂ emission. The electrochemical N₂ reduction reaction is an environmentally-benign alternative, which can be driven by renewable energy. In this work, CeO₂ nanoparticle–reduced graphene oxide nanocomposites (CeO₂–rGO) behave as an efficient non-noble-metal N₂ reduction reaction electrocatalyst with excellent selectivity. In 0.1 M Na₂SO₄, CeO₂–rGO achieves a high faradaic efficiency of 4.78% and a large NH₃ yield of 16.98 μg h⁻¹ mg_cat.⁻¹ at −0.7 V vs. reversible hydrogen electrode. The catalytic mechanism was explored using density functional theory calculations.