Effective and selective electrocatalytic nitrate reduction to ammonia on urchin-like and defect-enriched titanium oxide microparticles

FeNi3 nanoparticles for electrocatalytic synthesis of urea from carbon dioxide and nitrate

“…S21, ESI†), indicating that a C–N coupling reaction between CO 2 and NO 3 − was indeed occurred. 50–56…”

Ru-Loaded Biphasic TiO2 Nanosheet-Tubes Enriched with Ti3+ Defects and Directionally Deficient Electrons as Highly Efficient Catalysts in Benzene Selective Hydrogenation

“…Titanium mainly exists in the Ti 4+ state, while the detection of a Ti 3+ state aligns with the observations reported in EPR studies. Figure 4D exhibits the O 1s XPS spectra of the catalysts, and peaks near 530.0, 531.8, and 533.5 eV are attributed to lattice oxygen (O L ), oxygen vacancies (O V ), and adsorbed water (H 2 O) [24,38,42]. In conclusion, both EPR and XPS indicate the presence of a small amount of electron-deficient Ru δ+ , as well as Ti 3+ and O V on the Ru/TNSTs-t catalyst.…”

Recent Progress and Perspectives on Transition Metal-Based Electrocatalysts for Efficient Nitrate Reduction

“…The Ni 0.8 Cu 0.2 O@CuO@NF composites prepared by Hu et al 124 In addition, the oxygen vacancies (O v s) in metal oxides can achieve faster electron transfer 127 and stronger adsorption of oxygen atoms in nitrate, whereas O v s provide electrons for nitrogen in nitrate to promote adsorption and activation, thereby enhancing the catalytic performance. Tang et al 51 prepared sea urchin-like titanium dioxide particles (U-TiO 2 ) with surfaces enriched with O v s. Their NH 3 selectivity at −0.60 V was as high as 98.1%, which is higher than the selectivities of most previously reported catalysts, demonstrating that O v s are the true reaction sites for catalytic reactions, and they also facilitate the mass transfer process and electron transfer. This was also demonstrated in another study by Feng et al 123 By studying the heterogeneous interface of Cu/Co 3 O 4 with different oxygen vacancy concentrations, they found that medium O v concentrations of CoO x are the main active sites for hydrolysis dissociation and *H generation.…”

“…Different electrocatalyst materials may lead to different reduction pathways and principles, and the performances of the electrochemical nitrate reduction reactions produced by different electrocatalyst designs are also very different. Recent studies on electrocatalysts have focused on noble metal-based catalysts (e.g., Rh, − Ru, − Pd, , and Au − ), nonprecious metal-based catalysts (e.g., Cu, − Fe, ,− Co, − Ni, and Ti , ), and nonmetal-based catalysts − (organic polymers, carbon-based, boron-based, and phosphorus-based). The electrochemical nitrate reduction reaction of noble metal-based materials such as palladium is characterized by high activity, good durability, and high cost, but its performance is far from ideal and is not conducive to practical wastewater treatment.…”