The Relationship Between Carbon Nanotube Surface Status and Electrocatalytic Performance Toward Oxygen Reduction Reaction of Cobalt Phthalocyanine /Carbon Nanotube

Abstract

Recently, noble metals and their alloys nanoparticles supported on the carbon materials as carbon-based composite electrocatalysts are widely studied. However, on one hand, the high cost associated to these noble metals is still a drawback for full commercial application; on the other hand, their designing is limited by their characteristic. It is important to develop a new catalyst with low cost, high catalytic activity and wide designing for oxygen reduction reaction. Cobalt Phthalocyanine (CoPc) has high catalytic activity, and its special macrocyclic structure can perform well with the carbon materials toward Oxygen Reduction Reaction (ORR). Thus, the design of relationship between CoPc and its carbon-base is a necessary mission for this new catalyst for ORR. This abstract mainly focused on the different surface treatment of carbon nanotubes (CNTs) connect to CoPc and their electrocatalytic performance for the ORR process. Investigating raw CNTs, acidification CNTs (AF-CNTs) and activation CNTs gives us three different surface treatment CNTs coated by CoPc, which have higher electrocatalytic performance than CoPc itself. Here we find CoPc /AF-CNTs exhibit highest catalytic activity, and the Tafel Polarization curve test showed that CoPc/AF-MWCNTs perform the highest exchange current density (i0) in oxygen reduction reaction, and even its reaction rate is faster than commercial catalyst. The results indicated that the broken CNTs surface is beneficial for coating CoPc, as well as the charge transformation during the catalytic process. At the same time oxygen- containing groups on carbon-base can promote catalytic activity of CoPc for the ORR process. Figure 1