Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (10): 2263-2268.doi: 10.3866/PKU.WHXB201208171

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Nanocomposite Cathode Catalyst with High Methanol Tolerance and Durability

ZHENG Ning, ZHU Chun-Mei, SUN Bin, SHI Zu-Jin, LIU Yan, WANG Yuan   

  1. Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2012-07-09 Revised:2012-08-16 Published:2012-09-26
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20803001, 20973003, 51121091, 21133001), and National Key Basic Research Special Foundation of China (2011CB808702).

Abstract:

We report the preparation, characterization and elelctrocatalytic properties of a novel nanocomposite cathode catalyst (TiOPc-Pt/NSWCNH) which is assembled using Pt nanoclusters, TiOPc nanocrystal, and nitrogen-doped single walled carbon nanohorns (NSWCNHs) as building blocks. TiOPc-Pt/NSWCNH is characterized by inserting most of the Pt nanoparticles in nano-networks formed by stacking of NSWCNHs, and contacting of a part of the Pt nanoparticles with TiOPc nanocrystals. TiOPc-Pt/NSWCNH exhibits high electrocatalytic activity, excellent selectivity and durability for oxygen reduction reaction (ORR) in the presence of methanol. In an O2-saturated HClO4 aqueous solution containing methanol (0.5 mol·L-1), the onset potential over the TiOPc-Pt/NSWCNH catalyst shifted by more than 260 mV toward positive relative to that over a commercial Pt/C-JM catalyst. The mass activity and specific activity for ORR over TiOPc-Pt/NSWCNH at 0.85 V (versus a reversible hydrogen electrode (RHE)) was 83.5 A·g-1 and 0.294 mA·cm-2, respectively, which were much higher than those of Pt/C-JM. Cyclic voltammetry accelerated aging tests (0.6-1.0 V for 15000 cycles) in an O2-saturated HClO4 aqueous solution containing methanol revealed that TiOPc-Pt/NSWCNH possessed a higher durability compared to TiOPc-Pt/C. The high methanol tolerance of TiOPc-Pt/NCNH may be mainly derived from the electron transfer from TiOPc nanocrystals to Pt nanoparticles. The nano-network and the high graphitization degree of NSWCNHs are responsible for the excellent durability of TiOPc-Pt/NSWCNH.

Key words: Nanocomposite catalyst, Nitrogen-doped carbon nanohorns, Phthalocyanine, Durability, Methanol tolerance, Cathode of direct methanol fuel cells

MSC2000: 

  • O646.54