Efficient Metal-Free Oxygen Reduction in Alkaline Medium on High-Surface-Area Mesoporous Nitrogen-Doped Carbons Made from Ionic Liquids and Nucleobases

Abstract

Mesoporous nitrogen-doped carbon materials with high surface areas up to 1500 m(2) g(-1) were conveniently made by the carbonization of nucleobases dissolved in an all-organic ionic liquid (1-ethyl-3-methylimidazolium dicyanamide). Using hard templating with silica nanoparticles, this process yields high-surface-area nitrogen-doped carbon materials with nitrogen contents as high as 12 wt %, narrow mesopore size distribution of ca. 12 nm diameter, and local graphitic carbon structure. It is demonstrated that the resulting nitrogen-doped carbons show very high catalytic activity, even in the metal-free case in the oxygen reduction reaction (ORR) for fuel cells. Specifically, the as-prepared materials exhibit a low onset voltage for ORR in alkaline medium and a high methanol tolerance, compared with those of commercial 20 wt % Pt/C catalyst. We regard this as a first step toward an all-sustainable fuel cell, avoiding noble metals.

Nitrogen-doped graphene nanosheets as high efficient catalysts for oxygen reduction reaction

“…In addition, the kinetic current density at −0.25 V was calculated to be 23.2 mA/cm 2 based on the intercept of the Koutecky-Levich plots, which was wo times higher than that of the Pt/C catalysts (8.4 mA/ cm 2 ). It should be noted that the kinetic current density with NGNSs-900 also shows much higher than that of the previously reported mesoporous carbon, graphene and carbon nanotubes [12,13].…”

“…The recent innovation in this subject, by using vertically aligned nitrogen containing carbon nanotubes as the catalysts of ORR, seems to launch on a very promising path to develop cathode catalysts comparable with conventional Pt-based catalysts [11]. Afterwards, various nitrogen doped carbon nanostructures (NCNs), including carbon nanotubes cup, mesoporous graphitic array, and graphene etc., were successfully applied as catalysts of ORR in alkaline medium [12][13][14][15]. Despite of these abundant achievements, there are still at least two key issues concerning these NCNs serving as commercial cathode catalysts of fuel cell or metal air.…”

Preparation and properties of cotton stalk carbon/gold nanoparticles composite

“…As is known, nanoporous carbon materials with high surface area can be prepared by physical or chemical activation or templating method. [24,25] Herein, we present a universal method to prepare the carbon material with high surface area and abundant micropores. Activated carbon powder with a very high surface area is a promising candidate for the preparation of catalysts carriers.…”

Fe@N‐Graphene Nanoplatelet‐Embedded Carbon Nanofibers as Efficient Electrocatalysts for Oxygen Reduction Reaction

“…Although Pt and its alloys are considered the most effective electrocatalysts, having high intrinsic catalytic activity toward ORR,6, 7, 8, 9 they suffer from drawbacks of high cost and poor long‐term stability, which hinder the commercial expansion of Pt‐loaded batteries. In this regard, precious metal‐free catalysts such as carbon materials,10, 11, 12, 13 transition metal oxides,14, 15, 16, 17 and perovskite oxides18, 19 have been investigated as alternatives for the air electrode of metal‐air batteries.…”

“…In particular, heteroatom‐embedded carbons such as N‐doped carbon,10, 11 graphene,20, 22 and carbon nanofiber (CNF)16 have been considered as alternatives to Pt‐based catalyst because of their high catalytic property and durability for the ORR. Nitrogen‐doped graphene has attracted tremendous attention as an ORR electrocatalyst while also serving as a support because of its high electric conductivity, high catalytic activity toward the ORR, and unique structure.…”