Amino-functionalized hollow mesoporous silica supported Pd nanoparticles for efficient hydrogen production from formic acid

Hollow mesoporous silica nanospheres (HMSS) with radially ordered mesopores and isolated cavities were synthesized via a selective etching method. The surface of HMSS was functionalized with amino groups using 3-aminopropyltriethoxysilane (APTES) to obtain HMSS-NH 2 . Subsequently, palladium nanoparticles, palladium nanoparticles with an approximate mean size of 1.9 nm were deposited onto HMSS-NH 2 by means of an incipient wetness impregnation-reduction technique, yielding the Pd/HMSS-NH 2 catalyst. A systematic evaluation was conducted to assess the catalytic performance of the material in formic acid (FA) dehydrogenation. The findings indicate that the optimized Pd/HMSS-NH 2 catalyst (equipped with 10 wt% Pd content and 3 mL APTES) manifests an initial turnover frequency (TOF) of 3600 h −1  at 323 K for FA dehydrogenation, exhibiting an apparent activation energy as low as 29.3 kJ/mol. The full FA conversion and >99.99% H 2 selectivity were achieved under mild conditions. Furthermore, the catalyst retains good activity after five cycles. The superior activity of Pd/HMSS-NH 2 is attributable to the synergistic effect of the distinctive hollow mesoporous construction of HMSS and the surface amino groups, which effectively stabilize the active Pd nanoparticles. This investigation presents a novel strategy for engineering functional heterogeneous catalysts for hydrogen generation from FA.