Defective Au nanoparticles manipulated by Au-MgxAl-LDH interplay for alkali-free oxidation of benzyl alcohol

Supported gold catalyst, especially in terms of nanosized particles with defective surface and low-coordinated structure, plays a vital role in the heterogeneous catalysis. However, such defective Au nanoparticles are hardly acquired when supporting on non-reducible metal oxides/hydroxides due to insufficient Au-support interaction. In this work, we found that the defective Au NPs could be fabricated via the strong interplay between Au and crystal lattices of layered double hydroxides-MgxAl-LDH. Experimental and theoretical evidences revealed that the formation of a preferential-oriented LDH(0 1 5) plane enabled the surface configuration for defective Au centers with the maximized number of step sites at Mg/Al ratio of 3.0-3.5. The optimized Au/ Mg3.5Al-LDH catalyst shows a boosting catalytic activity for benzyl alcohol oxidation (TOF, 1008 h-1) at only 80 degrees C with the lowest activation energy in the absence of alkali. The work provides a new insight for manipulating the defective-enriched Au particles via the fine-tuning Au-LDH interplay for alkali-free selective oxidations.