Mesoporous Carbons Derived from Pyrolysis of Organosilica‐Based Ionogels for Oxygen Reduction Reaction

Abstract Developing of novel carbon‐based materials for electrocatalytic oxygen reduction reaction is highly important for sustainable energy conversion. In this work, iron‐containing ionogels were prepared from functional ionic liquid 1‐propionic acid‐2‐methyl imidazole bromide as the linker and an organically‐modified silica framework as the host, which were polymerized in the presence of iron(III) nitrate nonahydrate. The ionogels are mechanically stable, yellowish and transparent. After pyrolysis and washing by acid, unique mesoporous carbon materials were innovatively synthesized. Moreover, the as‐obtained carbon materials possess very high surface areas (1127 m 2 g −1 ), significant mesoporosity and abundant catalytic sites (e. g., effective N configurations). The optimal catalyst exhibits remarkable ORR activity with an onset potential (E onset ) of 0.98 V vs. RHE, a half‐wave potential (E 1/2 ) of 0.823 V vs. RHE and a diffusion‐limited current density (j L ) of 5.75 mA cm −2 in 0.1 M KOH, comparable to the commercial Pt/C catalyst in the same condition. This work provided a new strategy to fabricate promising electrocatalyts for application in fuel cells.