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以柠檬酸三钠为稳定剂,硼氢化钠为还原剂,制备了碳载型的Pd-Sb复合纳米催化剂(Pd-Sb/C),通过调制不同Pd:Sb摩尔比研究了其对甲酸电催化性能的影响.TEM结果表明,合成的纳米颗粒粒径较小且均匀分散在碳载体表面.XRD和XPS测试表明,Pd-Sb/C中少量的单质态Sb(0)高度分散在Pd颗粒中或表面,形成合金化程度较低的Pd Sb合金.电化学测试表明,当Pd:Sb=20:1时,合成的催化剂对甲酸的催化效能最佳.与合成的Pd/C和商业Pd/C相比,Pd-Sb/C(20:1)的电流密度分别是Pd/C的2.6倍、商业Pd/C的4.2倍.Pd-Sb/C的整体催化性能得到改善主要归因于适量的单质态Sb(0)引入到Pd中,诱导产生电子效应和“双功能”效应,一方面减小Pd与CO毒性物种之间的吸附作用,另一方面促使Pd表面吸附的CO快速氧化,提高了Pd-Sb/C催化剂的抗CO中毒能力,使得Pd-Sb/C催化剂的整体催化性能得到改善.
The Pd-Sb / C supported on carbon catalyst was prepared by using trisodium citrate as stabilizer and sodium borohydride as reducing agent. The catalytic activity of the Pd-Sb / C catalyst for formic acid The results of TEM showed that the synthesized nanoparticles were smaller and uniformly dispersed on the surface of the carbon support.XRD and XPS measurements showed that a small amount of elemental Sb (0) in Pd-Sb / C was highly dispersed in the Pd particles Or Pd Pd alloy with lower degree of alloying was formed.The electrochemical tests showed that the synthesized catalyst exhibited the best catalytic performance for formic acid when the molar ratio of Pd to Sb was 20 to 1. Compared with the synthesized Pd / C and commercial Pd The current density of Pd-Sb / C (20: 1) was 2.6 times that of Pd / C and 4.2 times that of commercial Pd / C, respectively, compared to that of Pd / C / C.The overall catalytic performance of Pd-Sb / C was mainly attributed to An appropriate amount of elemental Sb (0) is introduced into Pd to induce the electronic effect and the “dual function” effect. On the one hand, it reduces the adsorption between Pd and CO toxic species and on the other hand promotes the CO Rapid oxidation, improve the Pd-Sb / C catalyst anti-CO poisoning capacity, making the Pd-Sb / C catalyst overall catalytic performance is improved.