In-situ exsolved FeNi nanoparticles on perovskite matrix anode for co-production of ethylene and power from ethane in proton conducting fuel cells

A High-Performance and Durable Direct-Ammonia Symmetrical Solid Oxide Fuel Cell with Nano La0.6Sr0.4Fe0.7Ni0.2Mo0.1O3-δ-Decorated Doped Ceria Electrode

Solid oxide fuel cells (SOFCs) offer a significant advantage over other fuel cells in terms of flexibility in the choice of fuel. Ammonia stands out as an excellent fuel choice for SOFCs due to its easy transportation and storage, carbon-free nature and mature synthesis technology. For direct-ammonia SOFCs (DA-SOFCs), the development of anode catalysts that have efficient catalytic activity for both NH3 decomposition and H2 oxidation reactions is of great significance. Herein, we develop a Mo-doped La0.6Sr0.4Fe0.8Ni0.2O3-δ (La0.6Sr0.4Fe0.7Ni0.2Mo0.1O3-δ, LSFNM) material, and explore its potential as a symmetrical electrode for DA-SOFCs. After reduction, the main cubic perovskite phase of LSFNM remained unchanged, but some FeNi3 alloy nanoparticles and a small amount of SrLaFeO4 oxide phase were generated. Such reduced LSFNM exhibits excellent catalytic activity for ammonia decomposition due to the presence of FeNi3 alloy nanoparticles, ensuring that it can be used as an anode for DA-SOFCs. In addition, LSFNM shows high oxygen reduction reactivity, indicating that it can also be a cathode for DA-SOFCs. Consequently, a direct-ammonia symmetrical SOFC (DA-SSOFC) with the LSFNM-infiltrated doped ceria (LSFNM-SDCi) electrode delivers a superior peak power density (PPD) of 487 mW cm-2 at 800 °C when NH3 fuel is utilised. More importantly, because Mo doping greatly enhances the reduction stability of the material, the DA-SSOFC with the LSFN-MSDCi electrode exhibits strong operational stability without significant degradation for over 400 h at 700 °C.

Novel Perovskite Structured Nd0.5Ba0.5Co1/3Ni1/3Mn1/3O3-δ as Highly Efficient Catalyst for Oxygen Electrode in Solid Oxide Electrochemical Cells

Developing catalytic materials with highly efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for lower-temperature solid oxide fuel cell (SOFC) and electrolysis cell (SOEC) technologies. In this work, a novel triple perovskite material, Nd0.5Ba0.5Co1/3Ni1/3Mn1/3O3-δ, has been developed and employed as a catalyst for both ORR and OER in SOFC and SOEC operations at relatively lower temperatures, showing a low polarization resistance of 0.327 Ω cm2, high-power output of SOFC up to 773 mW cm-2 at 650 °C, and a high current density of 1.57 A cm-2 from SOEC operation at 1.5 V at 600 °C. The relaxation time distribution reveals that Nd0.5Ba0.5Co1/3Ni1/3Mn1/3O3-δ could maintain a slow polarization process at the relatively low operating temperature, offering a significant antipolarization advantage over other perovskite electrode materials. The Nd0.5Ba0.5Co1/3Ni1/3Mn1/3O3-δ electrode provides a low energy barrier of about 0.36 eV in oxygen ion mobility, which is beneficent for oxygen reduction/evolution reaction processes.

Laser Promoting Oxygen Vacancies Generation in Alloy via Mo for HMF Electrochemical Oxidation

It is well known that nickel-based catalysts have high electrocatalytic activity for the 5-hydroxymethylfurfural oxidation reaction (HMFOR), and NiOOH is the main active component. However, the price of nickel and the catalyst's lifetime still need to be solved. In this work, NiOOH containing oxygen vacancies is formed on the surface of Ni alloy by UV laser (1J85-laser). X-ray absorption fine structure (XAFS) analyses indicate an interaction between Mo and Ni, which affects the coordination environment of Ni with oxygen. The chemical valence of Ni is between 0 and 2, indicating the generation of oxygen vacancies. Density functional theory (DFT) suggests that Mo can increase the defect energy and form more oxygen vacancies. In situ Raman electrochemical spectroscopy shows that Mo can promote the formation of NiOOH, thus enhancing the HMFOR activity. The 1J85-laser electrode shows a longer electrocatalytic lifetime than Ni-laser. After 15 cycles, the conversion of HMF is 95.92%.

A promising Ruddlesden–Popper oxide cathode for both proton-conducting and oxygen ionic-conducting solid oxide fuel cells

A novel Nd1.8La0.2Ni0.74Cu0.21Ga0.05O4+δ cathode is developed for a proton-conducting solid oxide fuel cell with a high peak power density of 1.264 W cm−2 at 800 °C.