Alloying of gold with palladium: An effective strategy to improve catalytic stability and chlorine-tolerance of the 3DOM CeO2-supported catalysts in trichloroethylene combustion

The xAuPdy/3DOM CeO2 catalysts are prepared using the PMMA-templating and PVA-protected reduction methods. The excellent catalytic stability and chlorine-resistant performance of 2.85AuPd1.87/3DOM CeO2 for trichloroethylene oxidation is associated with its highly dispersed AuPd1.87 alloy NPs, high Oads species concentration, good low-temperature reducibility, and strong AuPd1.87-3DOM CeO2 interaction. [Display omitted] •AuPdy/3DOM CeO2 is prepared via PMMA-templating and PVA-protected reduction routes.•AuPdy alloy NPs with a size of 3–4 nm are highly dispersed on the 3DOM CeO2 surface.•2.85AuPd1.87/3DOM CeO2 shows the best catalytic activity for trichloroethylene combustion.•2.85AuPd1.87/3DOM CeO2 possesses good catalytic stability and H2O- and HCl-tolerant performance.•The strong AuPd1.87–3DOM CeO2 interaction is responsible for the good stability. The three-dimensionally ordered macroporous (3DOM) CeO2-supported Au–Pd alloys (xAuPdy/3DOM CeO2, x is the total loading (wt%) of Au and Pd, and y is the Pd/Au molar ratio) were synthesized using the polymethyl methacrylate-templating and polyvinyl alcohol-protected reduction methods. The samples were characterized by a number of analytical techniques, and their catalytic performance was evaluated for the combustion of trichloroethylene (TCE). It is found that the xAuPdy/3DOM CeO2 samples displayed a good-quality 3DOM architecture, and the noble metal nanoparticles (NPs) with a size of 3–4 nm were uniformly dispersed on the skeleton surface of 3DOM CeO2. Among all of the samples, 2.85AuPd1.87/3DOM CeO2 exhibited the highest catalytic activity, with the temperature at a TCE conversion of 90% (T90%) being 415 °C at a space velocity of 20,000 mL/(g h). Furthermore, the 2.85AuPd1.87/3DOM CeO2 sample possessed the lowest apparent activation energy (33 kJ/mol), excellent catalytic stability, and good moisture- and chlorine-tolerant behaviors. Alloying of Au with Pd changed the pathway of TCE oxidation and reduced formation of perchloroethylene. We conclude that the excellent catalytic performance for TCE combustion of 2.85AuPd1.87/3DOM CeO2 was associated with the highly dispersed AuPd1.87 alloy NPs, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between AuPd1.87 NPs and 3DOM CeO2 as well as the high-quality 3DOM structure and high surface acidity.