Modified cellulose nanocrystals immobilized AuPd nanoalloy for formic acid dehydrogenation

Formic acid (FA) is regarded as a promising liquid organic hydrogen transporter. Herein, carriers for immobilizing ultrafine AuPd nanoparticles with a size of approximately 2 nm were produced using cellulose nanocrystals (CNCs) treated with polydopamine (PDA) and polyethyleneimine (PEI). Even with a low noble metal loading (0.01 mmol), the optimized Au0.4Pd0.6/PEI-PDA@CNCs demonstrated extremely high FA dehydrogenation activity compared with similar products, with 100% hydrogen selectivity and TOFinitial up to 4258 h-1 at 323 K. The modified CNCs can enhance the electron transfer between metal particles, and their optimization of the local electronic structure can improve the adsorption of the key intermediates of the reaction. The density functional theory (DFT) calculations were discovered the optimized local electron environment promotes bi-HCOO* rearrangement and lowers the energy barrier for H* and H* binding. This discovery can be used to develop more effective catalysts in the future.