High-performance benzyl alcohol oxidation catalyst: Au-Pd alloy with ZrO2 as promoter

Achieving the balance between the catalytic activity and product selectivity still remains a challenge in partial oxidation processes, because the products are prone to be over-oxidized. Lewis acids (such as AlCl 3 ) have previously been identified to interact with C O groups, which can prevent the ketone products from further transformation. In this work, ZrO 2 promoted Au-Pd/γ-Al 2 O 3 catalyst was designed to enhance the benzaldehyde selectivity by generating more surface Lewis acid site on ZrO 2 -modified alumina. Results show that the introduction of ZrO 2 (5%) resulted in the formation of more surface Lewis acid sites, which improved the benzaldehyde selectivity through the strengthened interaction between the Lewis acid sites and C O groups in benzaldehyde. Besides, the addition of small amount of ZrO 2 enhanced the noble metal dispersion and led to the formation of more active sites to improve the oxygen transfer during the reaction.