不同pH值对直接乙醇燃料电池Pt-SnO2/C 电催化性能的影响

采用水热法制备了高分散Pt-SnO2/C电催化剂,对制备工艺进行了最佳优化,考察了不同反应溶液pH值对电催化剂活性的影响。采用XRD、SEM、TEM、比表面积、粒度分析等手段对催化剂进行了结构表征。制备的Pt-SnO2纳米复合颗粒高度分散在活性炭载体表面,其平均粒径约4.5nm。通过循环伏安、计时电流、交流阻抗等技术测试了电极在乙醇体系中的电催化活性。结果表明,随着反应溶液pH值的增加,制备的Pt-SnO2/C催化剂可使乙醇的氧化发生在较低电位。在pH值为9、铂锡原子比为3∶1时,制备的Pt-SnO2/C复合催化剂,可以得到较高的乙醇氧化电催化活性和电化学长期稳定性,氧化峰电流密度高达104.54mA·cm-2。     

Study of Sm0.2Ce0.8O1.9 （SDC） electrolyte prepared by a simple modified solid-state method

Sm0.2Ce0.8O1.9(SDC) electrolyte was prepared by a modified solid state method at relatively low sintering temperatures without any sintering promoters. The phase composition and microstructure of the electrolytes were investigated by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM) technologies. A relative density of SDC electrolyte sintered at 1300 oC reached 97.3% and the mean SDC grain size was about 770 nm. Their ionic conductivity and thermal expansion coefficient were also measured by electrochemical workstation and dilatometer. The electrolyte attained a high conductivity of 5×10–2 S/cm at 800 oC with an activation energy of 1.03 eV and a proper thermal expansion coefficient of 12.6×10–6 K–1.     

零维Pd基直接乙醇燃料电池催化剂的性能

以NaBH4为还原剂制备了Pd-Ru/C催化剂,研究不同Ru掺杂量对燃料电池阳极催化剂活性等的影响。利用XRD、EDS、TEM等技术表征催化剂的组成及微观结构;同时用BET等测试了催化剂的孔径和粒度分布。采用电化学工作站测试循环伏安特性来表征其电催化性能。测试结果表明,当Pd/Ru摩尔比为2∶1时,催化剂表现出最佳的抗中毒能力,电流稳定在50mA处,并且此时催化剂的电阻较小,具有较好的催化活性为207.40mA·cm-2。