关键词: Cu/N-C, 壳聚糖, 生物质资源, 催化剂, 氧还原反应, 碳浴法

Abstract:

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m ²·g^-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm³·g^-1. The most positive Gibbs free energy change was the rate determining step for ORR process with the 4e mechanism, where the value of the Cu(111)/N-C(-0.39 eV) was lower than that of the N-C(-0.26 eV). The Cu/N-C exhibited superior onset and half-wave potentials (0.96 V and 0.84 V, respectively) in alkaline media(0.1 mol·L^-1 KOH), all of which are much better than those measured for N-C and commercial Pt/C. Furthermore, the Cu/N-C showed superior methanol crossover avoidance and oxygen reduction stability.

Key words: Cu/N-C, chitosan, biomass resource, electrochemical catalyst, oxygen reduction reaction, carbon-bath method