Durable Electrocatalytic Reduction of Nitrate to Ammonia over Defective Pseudobrookite Fe₂TiO₅Nanofibers with Abundant Oxygen Vacancies

Abstract

We propose the pseudobrookite Fe2TiO5 nanofiber with abundant oxygen vacancies as a new electrocatalyst to ambiently reduce nitrate to ammonia. Such catalyst achieves a large NH3 yield of 0.73 mmol h−1 mg−1cat. and a high Faradaic Efficiency (FE) of 87.6 % in phosphate buffer saline solution with 0.1 M NaNO3, which is lifted to 1.36 mmol h−1 mg−1cat. and 96.06 % at −0.9 V vs. RHE for nitrite conversion to ammonia in 0.1 M NaNO2. It also shows excellent electrochemical durability and structural stability. Theoretical calculation reveals the enhanced conductivity of this catalyst and an extremely low free energy of −0.28 eV for nitrate adsorption at the presence of vacant oxygen.

PdP2 Nanoparticles on Reduced Graphene Oxide: A Catalyst for the Electrocatalytic Reduction of Nitrate to Ammonia

“…Therefore, the development of efficient and robust NRA catalysts is highly desirable to boost NO 3 – activation while suppressing the undesired HER. To this end, an increasing number of potential NRA catalysts have been explored, − with their performance further boosted by various strategies. − …”

Investigating the role of oxygen vacancies in metal oxide for enhanced electrochemical reduction of NO3− to NH3: mechanistic insights

“…101,102 Electron spin resonance (ESR) spectroscopy, also known as EPR spectroscopy, was utilized to detect OV signals in several different types of material. For example, in FTO-E (Fe 2 TiO 5 ) prepared by the electrospinning method and FTO-H (Fe 2 TiO 5 prepared by the hydrothermal method), the ESR signal exhibited peak values at g = 2.003, indicating the presence of OVs 103,104 (Fig. 5a).…”

“…106,172 Iron (Fe), a key component in the Haber–Bosch process, has been identified as a potential catalyst for nitrate reduction. In a recent study, Du et al 103 were inspired by the double-cation model and proposed the use of defective pseudobrookite Fe 2 TiO 5 nanofiber (FTO-E) as a new electrocatalyst to reduce nitrate to ammonia under ambient conditions. This electrocatalyst was prepared using the electrospinning technique and contains abundant oxygen vacancies (Fig.…”

Atomically isolated and unsaturated Sb sites created on Sb2S3for highly selective NO electroreduction to NH3

“…[36][37][38] Besides, defect engineering by creating vacancies or unsaturated sites is considered an effective strategy to tailor the electronic structure of catalysts with enhanced catalytic activities. [39][40][41] In view of the above, creating atomically isolated and unsaturated Sb sites is therefore an attractive strategy for designing high-efficiency NORR catalysts.…”