Nanomaterials Laboratory, Wolfson Centre, Brunel University, Uxbridge, Middx. UB8 3PH, UK.
Faraday Discuss. 2018 Sep 3;208(0):537-553. doi: 10.1039/c8fd00006a.
It is shown that water-in-oil microemulsions (m/e or μE) can produce BaCeO3 (BCO) and LaCoO3 (LCO) precursors. The nanoparticles (NPs) adsorb on AlOOH sols, in much the same way as Turkevich previously immobilised platinum group metal sols. BCO is active in CO and propane oxidation and NO removal under stoichiometric exhaust conditions, but LCO is a better oxidation catalyst. Activity was also seen when Ba,Ce and La,Co are inserted into/segregate at the surface of AlOOH/Al2O3. However, there is only formation of low levels of BCO, CAIO3 (CAO), LCO and LaAIO3 (LAO) perovskites, along with aluminates and separate oxides. The complexing of cations by AlOOH surface-held oxalate ions, albeit with different efficiencies, has also been explored. All three routes yield active catalysts with micro-domains of crystallinity; microemulsions produce the best defined perovskite NPs, but even those from surface segregation have higher turnover numbers than traditional Pt catalysts. Perovskite NPs may open up green chemistry for air pollution control that is consistent with a circular economy.
研究表明，油包水乳状液（微乳液或μE）可制备 BaCeO3（BCO）和 LaCoO3（LCO）前体。纳米颗粒（NPs）以类似于 Turkevich 先前固定的贵金属溶胶的方式吸附在 AlOOH 溶胶上。BCO 在化学计量废气条件下对 CO 和丙烷氧化及 NO 去除具有活性，但 LCO 是一种更好的氧化催化剂。当 Ba、Ce 和 La、Co 插入/隔离在 AlOOH/Al2O3 表面时，也观察到了活性。然而，只形成了低水平的 BCO、CAIO3（CAO）、LCO 和 LaAIO3（LAO）钙钛矿以及铝酸盐和独立氧化物。尽管效率不同，但 AlOOH 表面结合的草酸盐离子对阳离子的络合作用也得到了研究。所有三种途径都生成了具有微晶畴的活性催化剂；微乳液制备的钙钛矿 NPs 定义最明确，但即使是来自表面隔离的 NPs，其转化率也高于传统的 Pt 催化剂。钙钛矿 NPs 可能为符合循环经济的空气污染控制开辟绿色化学的新途径。
