TiO1.8 with lattice H for effective electrocatalytic nitrogen fixation

Titanium dioxide (TiO 2 ) is widely used as a representative transition metal oxides (TMOs) catalyst for electrocatalytic nitrogen reduction reaction (NRR). However, the low stability, low selectivity, low ammonia (NH 3 ) yield and high overpotential of TiO 2 towards NRR strongly restricted its application in NRR. Here, we firstly add H to the lattice to synthesize a black TiO 2−x with oxygen vacancies (OVs) (B-TiO 1.8 ) for electrocatalytic NRR. After we optimized the amount of H and OVs, the NH 3 yield and stability can achieve 31.6 μg h −1 mg cat −1 and 100 h at − 0.1 V ( vs . RHE), respectively, the faradaic efficiency (FE) can achieve 47.7% at 0 V ( vs . RHE). In situ FTIR / ESR / XPS / TPD illustrate that OVs can promote the adsorption and activation of nitrogen (N 2 ), and lattice H can increase the number of OVs and stabilize them, suppress the hydrogen evolution reaction (HER) and promote the hydrogenation of N 2 .