Fibrous porous carbon electrocatalysts for hydrazine oxidation by using cellulose filter paper as precursor and self-template

Abstract

Hydrazine is often regarded as one of the most appealing fuels for fuel cells due to its high energy content, and also because it gives off only environmentally benign byproducts when it is used in fuel cells (cf. many other fuels produce the greenhouse gas CO2). However, current electrocatalysts for the hydrazine oxidation reaction (HOR) in direct hydrazine fuel cells involve the expensive, unsustainable noble metals such as Pt. Herein, using cellulose filter paper both as a precursor and a self-template, we show the synthesis of nanoporous carbon electrocatalysts that can efficiently electrocatalyze HOR. To make the electrocatalysts, first cellulose filter paper is modified with metal-amine complexes and then with silica shells. After carbonization of the resulting composite material at different temperatures, followed by removal of the silica shells, nanoporous carbon-based electrocatalysts are obtained. Notably, the intertwined structure of the cellulose matrix in the filter paper is taken advantage of to serve as a self-template, allowing the formation of the desired fibrous, nanoporous carbon electrocatalysts. The materials show a good electrocatalytic activity toward HOR, giving a low overpotential and a high current density. Thus, such nanoporous carbons can be good candidate materials to replace conventional metal-based catalysts commonly used in HOR and other related reactions.