Metallic nanoparticles exsolved at the surface of perovskite oxides have been recently shown to unlock superior catalytic activity and durability towards various chemical reactions of practical importance. For example, for the CO oxidation reaction, exsolved Ni nanoparticles in oxidised form exhibit site activities approaching those of noble metals. This is of particular interest for the prospect of replacing noble metals with earth-abundant metal/metal oxide catalysts in the automotive exhaust control industry. Here we show that for the CO oxidation reaction, the functionality of exsolved Ni nanoparticles can be further improved when Fe is co-exsolved with Ni, as Fe–Ni alloy nanoparticles, eventually forming mixed oxide nanoparticles. As compared to the Ni nanoparticles, the alloy nanoparticles exhibit higher site activities, greatly improved durability over 170 h of continuous testing and increased tolerance towards sulphur-based atmospheres. Similarly to the single metal nanoparticles, the alloys demonstrate outstanding microstructural stability and high tolerance towards coking. These results open additional directions for tailoring the activity and durability of exsolved materials for the CO oxidation reaction and beyond.

最近已经证明，溶解在钙钛矿氧化物表面的金属纳米颗粒可以释放出优异的催化活性和持久性，从而对各种具有实际重要性的化学反应发挥作用。例如，对于CO氧化反应，氧化形式的溶解的Ni纳米颗粒表现出接近贵金属的位点活性。对于在汽车排气控制行业中用富含地球的金属/金属氧化物催化剂替代贵金属的前景，这尤其令人感兴趣。在这里我们表明，对于CO氧化反应，当Fe与Ni共溶时，作为Fe-Ni合金纳米颗粒，最终形成混合氧化物纳米颗粒时，可以进一步改善溶解的Ni纳米颗粒的功能。与Ni纳米粒子相比，合金纳米粒子具有更高的位点活性，在170小时的连续测试中大大提高了耐用性，并提高了对基于硫的气氛的耐受性。与单金属纳米颗粒相似，这些合金表现出出色的微观结构稳定性和对焦化的高耐受性。这些结果为调整溶解材料的活性和持久性提供了其他指导，以用于CO氧化反应及以后。