Robust hydrogen production from HCOOH over amino-modified KIT-6-confined PdIr alloy nanoparticles

Formic acid (FA), which can be produced via CO₂ reduction and biomass conversion, has received extensive interest as a convenient and safe hydrogen carrier due to its wide range of sources, renewable, high hydrogen content (4.4 wt%), and convenient storage/transportation. Designing highly efficient catalysts is the main challenge to realize the hydrogen production from FA. In this work, well-dispersed and electron-rich PdIr alloy nanoparticles with a size of 1.8 nm are confined in amino-modified 3D mesoporous silica KIT-6 and applied as a highly efficient catalyst for robust hydrogen production from FA at ambient temperature. Small PdIr alloy nanoparticles confined by amino-modified KIT-6 (PdIr/KIT-6-NH₂) lead to better catalytic activity compared to that of Pd/KIT-6-NH₂ and PdIr confined by bare KIT-6, achieving a high turnover frequency (TOF) value of 3533 h^?1 at ambient temperature (303 K), 100% H₂ selectivity and conversion toward the dehydrogenation of FA, which is comparable to the best heterogeneous catalysts ever reported. The high catalytic activity of PdIr/KIT-6-NH₂ can be attributed to the synergistic effect between Pd and Ir, strong interaction between PdIr and KIT-6-NH₂, as well as the amino-groups of KIT-6-NH₂ which can act as a proton scavenger to promote the breaking of O-H bond of formic acid.