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应用改进的多元醇法,分步还原制备表面富Pd的N iPd双元合金催化剂.研究表明:由于Pd较容易还原成核,且与N i的合金化程度低,Pd难以在N i颗粒表面实现单层包覆形成N i@Pd核壳结构,而是近似以单相的低合金化形式存在于N i颗粒表面,即形成N i@Pd(N i)的结构.与Pd/C相比,制备的N i@Pd(N i)/C催化剂,其Pd表面的氢吸附峰与吸收峰分辨清晰,含氧化物的脱附峰向正电势移动,氧还原活性显著提高.另外,N i的存在使Pd的抗甲醇性能明显增强,从而有望作为直接甲醇燃料电池的阴极催化剂.
Pd-based N iPd binary alloy catalyst was prepared by a step-by-step reduction method using an improved polyol method. The results show that Pd is more easily reduced to nucleate and has a lower degree of alloying with N i, (N i) is formed on the surface of N i particles in the form of single-phase low-alloyed structure, which is similar to that of Pd / C phase Compared with the prepared N i @ Pd (Ni) / C catalyst, the hydrogen adsorption peak and the absorption peak of the Pd surface are clearly distinguished, and the desorption peak of the oxide moves toward the positive potential and the oxygen reduction activity remarkably increases. The existence of i significantly enhances the anti-methanol performance of Pd, which is expected to be a cathode catalyst for direct methanol fuel cells.