Enhancing CO2 electrolysis through synergistic control of non-stoichiometry and doping to tune cathode surface structures

Abstract

Sustainable future energy scenarios require significant efficiency improvements in both electricity generation and storage. High-temperature solid oxide cells, and in particular carbon dioxide electrolysers, afford chemical storage of available electricity that can both stabilize and extend the utilization of renewables. Here we present a double doping strategy to facilitate CO2 reduction at perovskite titanate cathode surfaces, promoting adsorption/activation by making use of redox active dopants such as Mn linked to oxygen vacancies and dopants such as Ni that afford metal nanoparticle exsolution. Combined experimental characterization and first-principle calculations reveal that the adsorbed and activated CO2 adopts an intermediate chemical state between a carbon dioxide molecule and a carbonate ion. The dual doping strategy provides optimal performance with no degradation being observed after 100 h of high-temperature operation and 10 redox cycles, suggesting a reliable cathode material for CO2 electrolysis.

Highly efficient electrochemical reforming of CH 4 /CO 2 in a solid oxide electrolyser

“…The growth of metal nanoparticles drastically improves the current density to 1.2 A cm −2 at 1.5 V when optimum alloy compositions are obtained. These values are comparable to the performances of nickel-decorated (La,Sr)(Ti,Mn)O 3+δ cathodes and La 0.43 Ca 0.37 Ni 0.06 Ti 0.94 O 3+δ prepared with an electrochemical switching method ( 14 , 23 ). The in situ impedance spectra in fig.…”

“…In this case, any possible agglomeration of exsolved metal nanoparticles on the substrate can be remedied by periodically cycling from oxidizing to reducing conditions. The in situ growth of metal nanoparticles directly from a perovskite backbone support particularly exhibits enhanced high-temperature stability and coking resistance for CO 2 electrolysis due to the stronger metal/oxide interactions resulting from anchored interface architectures at the nanoscale ( 14 ). An additional way of improving catalytic performance with coking resistance is formation of alloy nanoparticles between Ni and other metals.…”

Direct Electrolysis of CO2 in a Symmetrical Solid Oxide Electrolysis Cell with Spinel MnCo2O4 as Electrode

“…In cathode side, CO or H 2 reducing atmosphere is necessary to prevent Ni from being oxidized. [16] To avoid these issues, cathode without Nibased cermet electrode has been tried. [15] The agglomeration and growth of Ni particles and the volume difference between Ni and NiO result in electrode degradation and delamination.…”

A numerical study of infiltrated solid oxide fuel cell electrode with dual‐phase backbone

“…Liang and coworkers fabricated a series of Pd infiltrated LSM‐YSZ (yttria‐stabilized zirconia) composite cathodes and the cell power density achieved 1.42 W cm −2 at 750°C in H 2 /air, which is almost 4 times higher than that of LSM‐YSZ cathode . Further investigation indicates that the deposition of Pd nanoparticles on the surface of the LSM‐YSZ backbone not only provides more reaction sites but also accelerates the reaction rate of the dissociation and diffusion of oxygen species . Besides, many studies show that improvement in the performance of infiltrated electrodes is correlated to the geometric properties of electrode microstructures, including three‐phase boundary (TPB) length and surface area of electrocatalytic particles.…”

“…12 Further investigation indicates that the deposition of Pd nanoparticles on the surface of the LSM-YSZ backbone not only provides more reaction sites but also accelerates the reaction rate of the dissociation and diffusion of oxygen species. 13 Besides, many studies show that improvement in the performance of infiltrated electrodes is correlated to the geometric properties of electrode microstructures, 14 including three-phase boundary (TPB) length and surface area of electrocatalytic particles. For an in-depth understanding of the geometric properties of infiltrated electrodes, characterization and prediction tools for electrode microstructures, such as X-ray microscopy, 15,16 stereology, 17,18 focused ion beam-scanning electron microscopy, [19][20][21] and theoretical modeling [22][23][24] are needed.…”