纳米Au粒子作为直接硼氢化钠-过氧化氢燃料电池阴极催化剂

采用浸渍还原法制备了纳米Au/C, 并将其用作直接硼氢化钠-过氧化氢燃料电池阴极催化剂. 通过X-射线衍射(XRD)和透射电镜(TEM)对催化剂进行结构和形貌分析, 结果表明10～20 nm的纳米Au粒子均匀地分散在Vulcan XC-72R碳黑表面上. 循环伏安测试表明, 在0.5 mol•L－1 H2SO4和2 mol•L－1 H2O2混合溶液中, 纳米Au/C在0.85 V处表现较强的不可逆还原电流. 以纳米Au/C为阴极催化剂, AB5储氢合金为阳极催化剂制成直接硼氢化钠-过氧化氢燃料电池. 电池在30 ℃下的最大功率密度可达到78.6 mW•cm－2. 当电池工作温度升高至50 ℃时, 电池的最大功率密度超过120 mW•cm－2. 此外, 研究了阴极溶液中H2SO4和H2O2浓度对电池性能的影响. 当阴极溶液中H2SO4浓度小于0.5 mol•L－1时, 酸浓度对电池性能影响较大; H2O2浓度对电池性能影响较小. 确定了阴极溶液中H2SO4和H2O2的最佳浓度分别为0.5和2 mol•L－1.

Performance of Nanosized Au Particle as a Cathode Catalyst for Direct Borohydride-hydrogen Peroxide Fuel Cell

Nanosized Au particles were prepared as a cathode catalyst for the direct borohydride-hydrogen peroxide fuel cell (DBHFC) by impregnation methods. The structure and surface morphology of the carbon-supported gold catalyst (Au/C) were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that 10～20 nm Au particles deposited on Vulcan XC-72R carbon black. The cyclic voltammogram (CV) results showed that the onset of reduction current on the Au/C occurred at 0.85 V in 0.5 mol•L－1 H2SO4 and 2 mol•L－1 H2O2. Also, a simple DBHFC was presented in which the Au/C was used as the cathode catalyst and a hydrogen storage alloy as the anode catalyst. The maximum power density of 78.6 mW•cm－2 was obtained at 30 ℃. When operated at 50 ℃, the DBHFC gave a higher than 120 mW•cm－2 power density. Furthermore, the effect of H2SO4 and H2O2 concentrations on the performance of DBHFC was described. The results exhibited that the performance of DBHFC had a strong dependence on the acid concentrations when H2SO4 concentration was lower then 0.5 mol•L－1, while the H2O2 concentrations had little influence on the performance of DBHFC. The results showed that the optimum concentrations of H2SO4 and H2O2 were 0.5 and 2 mol•L－1, respectively.