Fabrication of Pd–Au Clusters by In Situ Spontaneous Reduction of Reductive Layered Double Hydroxides

• Published in: Catalysis letters 2021-08, Vol.151 (8), p.2355-2365
• Main Authors: Chen, Shuai, Li, Haiping, Liu, Yanan, Feng, Junting, He, Yufei, Wang, Yanfei, Li, Dianqing
• Format: Article
• Language: English
• Subjects: Activation energy; Benzaldehyde; Benzyl alcohol; Bimetals; Catalysis; Catalysts; Chemistry; Chemistry and Materials Science; Coal; Cobalt; Gold; Hydroxides; Hydroxyl groups; Industrial Chemistry/Chemical Engineering; Nanoparticles; Organometallic Chemistry; Oxidation; Palladium; Physical Chemistry; Reaction time; Reducing agents; Reduction (metal working); Selectivity
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-020-03481-9

In this work, layered double hydroxides (LDHs) including the variable valence Co 2+ ions (CoAl-LDHs) is discovered to be capable of serving as the support and the reducing agent for the fabrication of well-distributed PdAu nanoparticles because of the low potential for reduction. Specifically, the active metal precursors undergo the redox process, in which Co 2+ is oxidized to Co 3+ , while active metal ions are successfully reduced to bimetallic PdAu nanoparticles with the dispersion of 73%. Furthermore, the obtained catalysts are evaluated in the selective oxidation of benzyl alcohol as the probing reaction to explore the catalytic behavior. As for intrinsic activity, PdAu/CoAl-LDHs derived by the above in situ spontaneous reduction exhibits activation energy of 62.4 kJ mol −1 , much lower than that of PdAu/CoAl-LDHs prepared by sol-immobilization. When the reaction time reaches to 4 h, the benzaldehyde selectivity over the former catalyst is up to 94%, originating from the surface electron starvation of active metals that promots the hydroxyl groups reacting with O 2 to produce benzaldehyde. Graphic Abstract