Nanocomposite Cathode Catalyst with High Methanol Tolerance and Durability

作者：Zheng Ning; Zhu Chun-Mei; Sun Bin; Shi Zu-Jin; Liu Yan^*; Wang Yuan

来源：Acta Physico - Chimica Sinica, 2012, 28(10): 2263-2268.

DOI：10.3866/PKU.WHXB201208171

• Nanocomposite catalyst
• Nitrogen-doped carbon nanohorn
• Phthalocyanine
• Durability
• Methanol tolerance
• Cathode of direct methanol fuel cell

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

• 出版日期2012-10
• 单位北京大学