碳化钨电极上氧的电催化还原

Electrocatalytic Reduction of Oxygen on Tungsten Carbide Electrode

以喷雾干燥微球化处理的偏钨酸铵作为前驱体,CO/H2为碳化还原气源,应用固定床气固反应法制备碳化钨(WC)粉体,再以聚四氟乙烯作粘结剂制成碳化钨电极.应用XRD和SEM等表征、观察碳化钨样品,循环伏安和线性扫描法研究硫酸电解液中WC电极的氧还原电催化行为.检测表明,WC为球状颗粒;WC电极对氧还原反应具有较好的电催化活性,硫酸溶液中溶解氧还原反应控制步骤为吸附态(O2-)ads的生成;增加硫酸电解液浓度,开路电位正移,升高温度有利于反应进行.

Tungsten carbide （WC） catalysts were state as precursors which were pretreated with spray prepared by gas-solid reaction using ammonium metatungdrying sphere miniaturation, carbon monoxide as carrier gas and hydrogen as deoxidizing gas. The WC electrode was fabricated using WC catalyst powders and PTFE as binding agent, and characterized by XRD and SEM. Electrocatalyst behavior of WC for oxygen reduction reaction in the sulphuric acid solution was studied by steady-state vohammetry and cyclic voltammetry. The results show that the WC powders obtained were in spheric particles and the prepared WC electrode had a good electrocatalyst ac- tivity to the oxygen reduction reaction. The electrode reaction was controlled by adsorption. The origination potential of oxygen reduction reaction being more positive, larger electrolyte concentration and higher temperature could promote the reaction.