Nanoengineering ABO₃active sites from low-energy routes (TX100-stabilised water-in-oil microemulsions, surface segregation and surface complexation on colloidal AlOOH/sol–gel Al₂O₃surfaces) for pollution control catalysis

Abstract

It is shown that water-in-oil microemulsions (m/e or mE) can produce BaCeO 3 (BCO) and LaCoO 3 (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/Al 2 O 3 . However, there is only formation of low levels of BCO, CAIO 3 (CAO), LCO and LaAIO 3 (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.

Water-in-oil microemulsion: effect of Desmodium intortum protein isolate–emulsifier interaction, and its stability

“…A rise in temperature promotes the conversion of the positive ions of protein into chalcone and consequently leads to protein degradation . [4,11,22] When the protein solution was under 60°C, the protein retention rate was only 13% after 15 d (p < .01). According to Figure 5B, Proteins exhibited a significantly increased retention rate of 63.5% at 60°C for 15 d after microemulsion embedding (p < .01).…”

“…Once the proportion is determined, a similar microemulsion can be produced. [11] The commonly used food-grade surfactants are soybean lecithin, Tween, span, and sucrose fatty acid ester . [12][13][14] Some studies have shown that the emulsifying effect on the stability of microemulsion of combined surfactant is better than that of a single surfactant, the stability of microemulsion is better.…”

“…Short-and middle-chain alcohols, such as ethanol, glycerol, and n-butyl alcohol, are multi-selected as cosurfactants in microemulsions. [3,6,11,14] This study aimed to determine whether the stability of W/O blank microemulsions can be improved by incorporating the protein isolate of Desmodium intortum into the aqueous phase based on the protein-emulsifier interface interaction. The W/O microemulsion was introduced into the complete W/O blank microemulsion to prepare W/O microemulsions with different protein concentrations for proteins and emulsifiers to compete for adsorption.…”