Green and active hydrogen production from hydrolysis of ammonia borane by using caffeine carbon quantum dot-supported ruthenium catalyst in methanol solvent by hydrothermal treatment

Abstract

Here, carbon quantum dot (CQD) supported Ru nanoparticles from the caffeine in methanol or water by the hydrothermal method were synthesized for the first time to produce hydrogen (H-2) by hydrolysis of ammonia borane(NH3BH3) and their catalytic activities were investigated. The chemical compositions and morphology structures of this caffeine carbon dot-supported Ru catalysts were carefully characterized by UV, PL, TEM, FTIR, and ICP/OES analyses. Well-dispersed Ru nanoclusters with similar to 1.81 nm particle size on CQD by the hydrothermal method in methanol medium showed very good catalytic performance. The turnover frequency (TOF) obtained for H-2 production from the catalytic hydrolysis of 5% NH3BH3 with CQD supported Ru catalyst obtained by the hydrothermal method in methanol and water was found to be 361 and 1895 mol H-2 min(-1) mol(-1), respectively. The activation energies (Ea) for NH3BH3 hydrolysis with the same catalysts were measured as 33.32 and 27.80 kJmol(-1), respectively.