Metal-metal oxide synergistic catalysis: Pt nanoparticles anchored on mono-layer dispersed ZrO2 in SBA-15 for high efficiency selective hydrogenation

Abstract

It is generally believed that noble metal catalysts exhibited higher activity for selective hydrogenation, while metal oxides were almost inactive. Here, we report metal-metal oxide synergistic catalysis for high efficiency selective hydrogenation by a hybrid nano-structure Pt/@-ZrO2/SBA-15 catalyst, which was fabricated by anchored Pt nanoparticles on the mono-layer dispersed ZrO2 film layer coated in SBA-15 support via a photochemical route. This Pt/@-ZrO2/SBA-15 catalyst exhibited remarkable catalytic activity in the selective hydrogenation of CO bond, NO2, and CC bond. For the selective hydrogenation of benzaldehyde, conversion >99.9% was achieved with >99% selectivity, and the turnover frequency (TOF) can be achieved up to 4822 h−1, which was much higher than that of the atomically dispersed Pd1/TiO2-EG catalyst (1002 h−1) reported in the literature, no decay in the activity was observed by several cycles. Combined the experimental and characterization results, proved that the ZrO2 was dispersed in a mono-layer in the channel of SBA-15, and the results showed that an appropriate loading of ZrO2 in this catalyst could maximize the advantage of this hybrid nano-structure to achieve the best catalytic activity. The superior activity of Pt/@-ZrO2/SBA-15 was attributed to the synergistic catalysis, strong interface electronic effect, and the unique properties of the special hybrid nano-structure. This work demonstrated synergistic catalysis of metal Pt nanoparticles and monolayer dispersion ZrO2 for high efficiency selective hydrogenation.