羟基锡酸盐载铂复合催化剂Pt/(Co,Zn)Sn(OH)6的合成及其甲醇电催化氧化性能

以羟基锡酸盐CoSn（OH）₆和ZnSn（OH）₆纳米空心立方体为前体，采用抗坏血酸作为弱还原剂，经过超声过程分别合成了羟基锡酸钴载Pt/CoSn（OH）₆和羟基锡酸锌载Pt/ZnSn（OH）₆复合催化剂，并在甲醇氧化反应（MOR）中表现出良好的性能。Pt/CoSn（OH）₆和Pt/ZnSn（OH）₆催化剂的单位质量活性分别为1 095.6 mA/mg和699.5 mA/mg，高于C载Pt（Pt/C）的594.6 mA/mg。利用XRD、SEM、TEM、XPS和电化学测试对催化剂晶体结构和性能间的关系进行了探索。CO溶出实验结果表明，羟基锡酸盐载体有利于Pt表面CO的去除，载体与Pt间的强相互作用和载体表面的大量羟基基团增强了催化剂的催化活性和CO抗毒性。此外，Pt/（Co，Zn）Sn（OH）₆催化剂中单质Pt高的相对含量也有利于提高MOR活性。通过研究载铂羟基锡酸盐电催化氧化甲醇性能，能够揭示载体结构对催化性能的影响，有助于羟基锡酸盐载铂复合催化剂在直接甲醇燃料电池（DMFCs）领域的应用。

Synthesis of Pt/(Co,Zn)Sn(OH)6 complex catalysts and their catalytic activity towards methanol electrochemical oxidation

The Pt/CoSn(OH)₆ and Pt/ZnSn(OH)₆ complex catalysts were prepared using CoSn(OH)₆ and ZnSn(OH)₆ hollow nanocubes by an ultrasound process with ascorbic acid as the soft reductant, respectively, and demonstrate excellent performance towards the methanol oxidation reaction (MOR). The Pt/CoSn(OH)₆ and Pt/ZnSn(OH)₆ catalysts exhibit higher mass activities (1095.6 mA/mg and 699.5 mA/mg, respectively) compared to Pt/C (594.6 mA/mg) catalyst towards methanol oxidation. XRD, SEM, TEM, XPS and electrochemical measurements were employed to explore the relationships of the crystal structure and the properties of catalysts. CO-stripping experiment results indicate that the hydroxide supports facilitates the removal of CO on Pt surface. The increased activity and resistance of CO poisoning for Pt/CoSn(OH)₆ and Pt/ZnSn(OH)₆ catalysts can be attributed to the strong interaction between the support (Co, Zn)Sn(OH)₆ and Pt in the catalysts and the large amount of hydroxyls on the support surface. The higher relative intensity of Pt in the (Co, Zn)Sn(OH)₆ catalysts also contributes to the higher MOR activity. The (Co, Zn)Sn(OH)₆ towards methanol catalytic electro-oxidation can disclose the influence of the support structure on the catalytic activity and will be helpful for the development and application of complex catalysts in direct methanol fuel cells (DMFCs).