The electrochemical promotion of nitrous oxide reduction on a lanthanum strontium iron cobalt cathode

Abstract

Summary Nitrous oxide (N2O) is a potent greenhouse gas and suitable methods for its mitigation are urgently required. For this reason, we study the electrochemical promotion of N2O reduction on a La0.6Sr0.4Co0.2Fe0.8O3‐δ (LSCF) electrocatalyst. N2O decomposition was studied in the temperature range 600‐800°C, at ambient pressure, under applied polarization in galvanostatic mode. The results reveal the highest conversion increment factor of 13.12 at 600°C when a current of −0.25 A was applied. The Faradaic efficiency (|Λ|) was calculated for the tested experimental conditions and shows values that exceed unity, evidencing Non‐Faradaic Electrochemical Modification of Catalytic Activity (NEMCA) for the N2O reduction reaction. The nature of the mechanism was also assessed, showing a completely reversible effect, where the electrochemically promoted reaction rate returns to its open circuit (unpromoted) value upon removal of the applied polarization. The current work shows that the existence of the NEMCA effect can be a highly beneficial factor for the electrochemical treatment of this green‐house gas, with a valuable potential for mitigation of exhaust gases.

Immobilized Nanomaterials for Environmental Applications

“…Its concentration in the atmosphere has been augmented 18% since the preindustrial level, mainly due to human activities, such as the extensive application of fertilizers and burning of fossil fuels. Consequently, European Union edicts aim at its 42% reduction by 2030, with respect to 2013 emission data [ 74 ].…”

“…For instance, the deposition of Os and Pt NPs to create a stable film on the surface of different electrode materials was accomplished, and the doped electrodes were effective for reducing N 2 O to dinitrogen gas (N 2 ) [ 79 ]. Lately, the reduction of N 2 O to N 2 was also achieved on the surface of a cathode enriched with La, Sr, Fe, and Co [ 74 ]. The mechanism involved in this electrochemical process was elucidated, showing that the catalytic rate returns to its open circuit value after polarization.…”