以铂基高指数晶面纳米晶为载体负载过渡金属催化甲醇电氧化

Platinum nanocrystals enclosed high-index facet as a carrier to support transition metal particles for methanol electrooxidation

易于重构的Pt基高指数晶面(HIF)的结构不稳定,基于此提出将一种或多种非贵金属作为活性助剂负载到与HIF结合的贵金属纳米晶体的表面,以设计、制备稳定结构的纳米催化剂。以Pt3Mn凹面立方体为载体,引入非贵金属Sn,制备了Sn/Pt3Mn催化剂,采用XRD和TEM对其进行了表征,考察了催化剂的甲醇电氧化催化性能,探讨了催化剂的结构与性能的关系。实验结果表明,与Pt3Mn凹面立方体和市售Pt/C催化剂相比,Sn/Pt3Mn催化剂对甲醇电氧化的催化活性显著提高,且稳定性增强;Sn质量分数为0.5%的Sn/Pt3Mn催化剂的面积比活性是Pt3Mn凹面立方体的2.84倍。

The Pt-based nanocrystals exposed high-index facet(HIF)are easy to reconstruct and rearrange during the reaction due to their high surface energy and insufficiently coordinated surface atoms,which is a major obstacle for further practical catalytic applications.In this work,a new strategy is addressed that the stable-structured catalyst is engineered by supporting one or more non-noble metals as active additives into the surface of the precious metal nanocrystals enclosed with HIF.Sn/Pt3Mn catalyst was prepared by using Pt3Mn concave nanocube(CNC)as support and introducing non-noble metal Sn.The catalyst was characterized by XRD and TEM.Its catalytic performance of methanol electrooxidation was studied.The relationship between structure and performance of Sn/Pt3Mn catalyst was discussed.The result shows that the catalytic activity of Sn/Pt3Mn catalyst for methanol is much higher than those of Pt3Mn CNC and commercial Pt/C catalysts.Importantly,the stability is also enhanced.The area-specific activity of 0.5%(w)Sn/Pt3Mn catalyst is 2.84 times higher than that of pure Pt3Mn CNC.