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用氩离子溅射法所制备的Pd/C和Pd/Al_2O_3两种模型催化剂,在氢气中进行热处理,用电镜测定结果表明,随着加热温度的升高两者晶粒大小和物相的变化有很大差别。前者晶粒长大速度快,在高温下Pd仍以原子形式担载在活性炭表面上,未形成新的物相,而后者晶粒长大速度慢,Pd与Al_2O_3发生电子交换形成新的物相,这意味着Pd在炭和Al_2O_3表面上的相互作用不同而导致抗烧结性能的差异。
The Pd / C and Pd / Al 2 O 3 catalysts prepared by argon ion sputtering were heat-treated in hydrogen. The results of electron microscopy showed that with the increase of heating temperature, the crystallite size and phase change There is a big difference. The former grows rapidly. At high temperature, Pd is still supported on the surface of activated carbon in atomic form. No new phase is formed, while the latter grows slowly. Electron exchange between Pd and Al 2 O 3 forms a new phase , Which means that the interaction of Pd on the surface of carbon and Al 2 O 3 is different and leads to the difference of the sintering resistance.