Development of Refractory Ceramics for the Oxygen Evolution Reaction (OER) Electrocatalyst Support for Water Electrolysis at Elevated Temperatures

Abstract

Commercial TaC and Si3N4 powders were tested as possible electrocatalyst support materials for the Oxygen Evolution Reaction (OER) for PEM water electrolysers, operating at elevated temperatures. TaC and Si3N4 were characterised by thermogravimmetric and differential thermal analysis for their thermal stability. The Adams fusion method was implemented to deposit IrO2 on the support surfaces. A series of electrocatalysts was prepared with a composition of (IrO2)x(TaC/ Si3N4)1-x,where x represents the mass fraction of IrO2 and was equal to 0.1 (only for TaC), 0.3, 0.5, 0.7, 0.9 and 1. The thin-film method was used for electrochemical analysis of the prepared electrocatalysts. SEM-EDX, BET and powder conductivity measurements were used as complementary techniques to complete characterisation of the electrocatalysts. Additionally, they were compared in their properties with previously reported data for a SiC-Si support. The stability of the electrocatalysts was assessed by estimation of reversibility of the anodic/cathodic processes.

Supported Iridium‐based Oxygen Evolution Reaction Electrocatalysts ‐ Recent Developments

“…Another nitride support was based on silica, Si 3 N 4 , but only a slight enhancement of electrochemical performances was recorded [210] . It was most likely due to the low interaction between the support and IrO 2 as well as the low conductivity of Si 3 N 4 alone.…”

“…Another nitride support was based on silica, Si 3 N 4 , but only a slight enhancement of electrochemical performances was recorded. [210] It was most likely due to the low interaction between the support and IrO 2 as well as the low conductivity of Si 3 N 4 alone. Other nitride supports for Ir‐based catalysts were investigated in alkaline media and are thus out of the scope of this review.…”

Effect of Electronic Conductivities of Iridium Oxide/Doped SnO2 Oxygen-Evolving Catalysts on the Polarization Properties in Proton Exchange Membrane Water Electrolysis

“…It is essential to develop new anode catalysts that utilize Ir more effectively, working toward much higher mass activity (MA, current per mass of noble metal) for the OER, as well as high durability, while clarifying the reaction mechanisms [11,12]. In order to increase the MA, iridium or iridium oxide (IrO x ) nanoparticles have been mixed or dispersed on various supports such as metal carbides [13][14][15] and oxides [16][17][18][19][20][21][22]. Considering the stability at the high oxygen-evolving potentials in strong acidic media and the need for high electronic conductivity, doped tin oxides have been reported as promising candidates as support materials [23,24].…”

Effect of Electronic Conductivities of Iridium Oxide/Doped SnO₂ Oxygen-Evolving Catalysts on the Polarization Properties in Proton Exchange Membrane Water Electrolysis

“…It is essential to develop new anode catalysts that utilize Ir more effectively, working toward much higher mass activity (MA, current per mass of noble metal) for the OER, as well as high durability, while clarifying the reaction mechanisms [11,12]. In order to increase the MA, iridium or iridium oxide (IrOx) nanoparticles have been mixed or dispersed on various supports such as metal carbides [13][14][15] and oxides [16][17][18][19][20][21][22]. Considering the stability at the high oxygen-evolving potentials, stability in strong acidic media, and the need for high electronic conductivity, doped tin oxides have been reported as promising candidates as support materials [23,24].…”