炭载体前处理对Pt-Ru/C催化剂性能影响

为研究水蒸气处理后热处理对炭黑表面特性的影响,提高DMFC阳极催化剂的催化活性,利用先水蒸气处理后热处理的Vnlcan XC-72炭黑为载体制备Pt-Ru/C催化剂,与水蒸气处理的和未经处理的炭载体制备Pt-Ru/C催化剂的性能进行比较.采用XPS和BET测试了处理后的炭粉表面的含氧浓度和比表面,结果表明：水蒸气处理后,炭载体比表面积增大,含氧浓度降低;水蒸气处理后热处理,炭载体比表面积进一步减小,含氧浓度增加.用XRD对催化剂的结构进行了表征,结果表明：水蒸气处理后热处理的炭黑为载体制备Pt-Ru/C催化剂结晶状态良好,催化剂颗粒较小.在0.5mol/L CH3OH和0.5mol/L H2SO4混合溶液中,利用玻炭电极测试了循环伏安曲线和阶跃电位曲线,结果表明：用先水蒸气处理后热处理的炭粉为载体制备的催化剂比仅水蒸气处理和未经处理的炭粉为载体制备的催化剂的活性最高.

INFLUENCE OF CARBON SUPPORT PRETREATMENT ON Pt-Ru/C CATALYSTS

This research aims to increase the utilization of platinum-ruthenium alloy (Pt-Ru)catalysts and thus to lower the catalyst loading in the electrode for methanol electrooxidation. The Vulcan XC-72 carbon black supported Platinum-ruthenium catalysts were prepared by chemical reduction method. The support was pretreated by water vapor and then thermal treatment. The specific surface area of the samples was evaluated using the standard BET method. The oxygen-containing concentrations and its groups were determined by XPS. It showed that the oxygen-containing concentrations in carbon by water vapor treatment were increased,and specific surface area of carbon was decreased. The specific surface area of carbon by water vapour and then thermal treatment was decreased, and oxygen - containing concentrations in it were increased. X-ray diffraction(XRD) was used to characterize the influence of carbon treated with water vapor and then thermal treatment onPt -Ru/C catalysts. It was found that the particle size of catalyst support carbon for water vapor and then thermal treatment is small. Pt-Ru/C catalysts supported on untreated and treated carbons black were characterized and tested for methanol electrooxidation. In a solution of 0. 5mol/L CH3OH and 0. 5mol/L H2SO4, cyclic voltammetry(CV) and chronoamperometric curves for methanol electrooxidation on the Pt-Ru/C catalysts show that the catalytic activity of Pt-Ru/C catalysts support treated by water vapor and then thermal temperatures is higher than Pt - Ru/C catalysts support untreated and only water vapor.