摘要：Chemoselective hydrodeoxygenation of vanillin is of great importance in converting biomass into high value-added ***,we describe a facile photochemical route to access palladium single atoms and clusters supported on silicoaluminophosphate-31(SAPO-31)as a highly active,chemoselective,and reusable catalyst for hydrodeoxygenation of *** by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy,extended X-ray absorption fine structure measurement,and CO-absorbed diffuse reflectance infrared Fourier transform spectroscopy reveal the atomically dispersed palladium single atoms and clusters are loosely bonded and randomly dispersed,without forming strong palladium-palladium metallic bonding,over the SAPO-31 *** catalyst,with a full metal availability to the reactants,exhibits exceptional catalytic activity(TOF:3,000 h^(−1),Yield:>99%)in the hydrodeoxygenation of vanillin toward 2-methoxy-4-methylphenol(MMP)under mild conditions(1 atm,80°C,30 min),along with excellent stability,scalability(up to 100-fold),and wide substrate *** superior catalytic performance can be attributed to the synergistic effect of the positively charged palladium single atoms and fully exposed clusters,as well as the strong metal-support *** work may offer a new avenue for the design and synthesis of fully exposed metal catalysts with targeted functionalities.

摘要：Tuning the electronic properties of single atom catalysts(SACs)between the central metal and the neighboring surface atoms has emerged as an efficient strategy to boost catalytic efficiency and metal *** we describe a simple and efficient approach to create atomically dispersed palladium atoms supported over defect-containing porous ceria nanorod containing palladium up to 0.26 wt.%.The existence of singly dispersed palladium atoms is confirmed by spherical aberration correction electron microscopy and extended X-ray absorption fine structure *** catalyst shows excellent efficiency in hydrodehalogenation reactions at low H2 pressure under mild conditions,along with satisfactory recyclability and *** functional theory(DFT)calculations reveal that the high activity stems from the spatial isolation of palladium atoms and the modified electronic structure of palladium confined in defect-containing ceria *** work may lay the foundation for the facile creation of single atom catalysts within the synthetic community and shed light on the possibility for scale-up production.