燃料电池阴极氧还原反应(ORR)的电子转移过程比较复杂,反应动力学缓滞,需要高效的电催化剂来加快反应速率.传统的贵金属铂基催化剂价格昂贵,因此亟需开发高性能、低成本的非贵金属催化剂作为替代材料.首先通过溶胶凝胶和热处理,得到了尺寸约为10 nm的氧化铈/镍复合纳米颗粒,然后通过催化甲烷热分解,得到了碳纳米管支撑的氧化铈/镍纳米材料.由于碳纳米管的形成,使催化剂与电解液的接触面积增加,并且改变了金属镍的电子结构,从而使其在碱性溶液中表现出较好的电催化氧还原活性,其循环伏安的氧还原峰电位约在-0.17 V和-0.51 V左右,氧还原极化曲线的开启电位约在-0.05 V vs.SCE.
Preparation and Performance of Cerium Oxide/Nickel-Carbon Nanotube Composite Oxygen Reduction Electrocatalyst
The electron transfer process of oxygen reduction reaction in fuel cells cathode is complex and the reaction kinet-ics are slow,thus needing efficient electrocatalysts to accelerate the reaction rate.Traditional precious metal platinum-based catalysts are expensive,so there is an urgent need to develop high-performance and low-cost non-precious metal catalysts as alternatives.In this paper,cerium oxide/nickel nanocomposite nanoparticles with a size of about 10 nm were ob-tained by sol-gel method and heat treatment,and then cerium oxide/nickel nanomaterials supported by carbon nanotubes were obtained by catalyzing methane thermal decomposition.Benefiting from the carbon nanotubes production,the contact area between the catalyst and the electrolyte increases,and the electronic structure of nickel is changed.Consequently,it shows good electrocatalytic oxygen reduction activity in alkaline solution,and the oxygen reduction peak potential of cyclic voltammetry is about-0.17 V and-0.51 V,and the onset potential of the oxygen reduction polarization curve is about-0.05 V vs.SCE.
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