Electrooxidation of Formaldehyde on Silver/Ordered Mesoporous Carbon Composite Electrode in Alkaline Solutions

Abstract

—Metal nanocatalysts, as the anodic materials, have become increasingly important in fuel cells, due to their unique physical and chemical properties. Here, the porous silica was employed as a hard template to prepare the ordered mesoporous carbon (CMK-3). The as-prepared CMK-3 has a large surface area of 877 m2/g and the hierarchical porous structure with the pore size distribution centered at 3.7 nm. The CMK-3 supported silver nanocatalysts have been prepared through the wet chemical reduction by using the reduction of formaldehyde. The electrochemical properties of the Ag/CMK-3 nanocatalysts for formaldehyde oxidation are studied by cyclic voltammerry (CV) and chronoamperometric curves (i-t) in alkaline aqueous solutions. The results show that the peak current density (CV) of the Ag/CMK-3 electrode is 112 mA/cm2, above 2 times higher than that of Ag/XC-72 at the same Ag loading (14.15 μg/cm2). Furthermore, i-t curves demonstrate that the Ag/CMK-3 nanocatalysts are efficient and stable electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. Therefore, Ag/CMK-3 nanocatalysts with the improved electrocatalytic activity suggest their application potential towards fuel cells and sensors.