Electrocatalytic Oxidative Coupling of Methane on NiFe Exsolved Perovskite Anode: Effect of Water

Abstract

Oxidative coupling of methane (OCM) can be performed electrocatalytically by utilizing solid oxide cells, which provide a readily controlled oxygen supply through dense electrolytes. La0.7Sr0.2Ni0.2Fe0.8O3 (LSNF) perovskite is an effective anode for OCM. Its surface characteristics and electrocatalytic activity can be improved by reduction and the resultant exsolution of bimetallic NiFe nanoparticles from its bulk. X‐ray diffraction (XRD) and environmental transmission electron microscopy proved that the evolution of hetero‐phases under reducing environment resulted in bimetallic NiFe nanoparticles being formed on the surface. A 36 % improvement in C2+ hydrocarbon production rate was achieved due to the reduction of LSNF with the exsolved NiFe nanoparticles. Co‐feeding of H2O enhanced selective conversion of CH4 resulting in the production rate of C2+ hydrocarbons being increased by 56 %. Analysis of impedance spectra and in‐situ DRIFTS under a CH4+H2O atmosphere provided an understanding for the enhancement on the electrocatalytic OCM.

Enhanced catalysis of a vanadium-substituted Keggin-type polyoxomolybdate supported on the M3O4/C (M = Fe or Co) surface enables efficient and recyclable oxidation of HMF to DFF

“…This indicates that during the solvothermal reaction process, some of the surface oxygen atoms of Fe 3 O 4 /C were replaced by the terminal oxygen atoms of PMo 10 V 2 . 75,76 It can be observed that the hydroxyl peak of PMo 10 V 2 is located at 3430 cm −1 and the hydroxyl peak of S1 and S2 †).…”

Advancements in Environmentally Sustainable Technologies for Ethylene Production

“…The synthesized catalyst achieved only 19% ethylene selectivity in a tubular solid oxide fuel cell, as shown in Figure 18. Kim et al 123 utilized reduced as a La 0.7 Sr 0.2 Ni 0.2 Fe 0.8 O for exsolving the NiFe nanoparticles on the surface in a solid oxide cell. This modification led to the electrocatalytic performance of ∼54% C 2 + selectivity at 800 °C.…”

ANbO3 (A = Na, K) and (A′ = Ca, Sr) composite oxides for oxidative coupling of methane and oxidative dehydrogenation of ethane: perovskite vs. layered perovskite

“…In addition, both regular and layered perovskites exhibit high-temperature stability and are excellent oxygen ion conductors, allowing them to meet the active site requirements for oxidative coupling of methane (OCM) and oxidative dehydrogenation of ethane (ODHE). [15][16][17][18][19][20][21][22] Thus, many of these perovskites exhibit a good catalytic performance for OCM and ODHE. Our previous research on ABO 3 perovskites and A 2 B 2 O 7 -type oxides revealed that when A-site cations are alkali metal cations (Na + or K + ) and the B-site cations are Nb 5+ ions, a 1 : 1 stoichiometric ratio of A and B can produce a regular perovskite structure (NaNbO 3 and KNbO 3 ) with orthorhombic crystal phases.…”