TiS2 nanosheets for efficient electrocatalytic N2 fixation to NH3 under ambient conditions

Abstract

Currently, the energy and capital intensive Haber–Bosch process still dominates NH₃ synthesis which operates at high temperatures and pressures releasing inevitably large amounts of CO₂. The electrocatalytic N₂ reduction reaction (NRR) offers us an environmentally-friendly and sustainable route for NH₃ synthesis under ambient conditions. In this communication, we describe that TiS₂ nanosheets (TiS₂ NSs) behave as efficient transition-metal-based NRR electrocatalysts for N₂-to-NH₃ conversion with excellent selectivity. When tested in 0.1 M Na₂SO₄, such TiS₂ NSs achieve a high faradaic efficiency of 5.50% and a large NH₃ yield of 16.02 μg h⁻¹ mg⁻¹_cat at −0.6 V vs. reversible hydrogen electrode, which is superior to bulk TiS₂ (5.84 μg h⁻¹ mg⁻¹_cat; 1.66%). Notably, this catalyst also shows strong stability during electrolysis and recycling tests.