MIL-101 metal organic framework stabilized palladium(0) nanoclusters: Synthesis, characterization and investigation of their catalytic performance in the methanolysis of ammonia-borane

Palladium(0) nanoclusters stabilized by metal-organic framework (Pd@MIL-101) were prepared by wet-impregnation followed by simultaneous reduction with sodium borohydride at room temperature. The characterization of the resulting Pd@MIL-101 material was done by using multi-pronged analyses including ICP-OES, EA, P-XRD, XPS, DR-UV–vis, BFTEM, HRTEM, STEM-EDX and N2 adsorption–desorption technique, which revealed that the formation of palladium(0) nanoclusters (5.6 ± 2.2 nm) within the framework of MIL-101 by keeping the host framework intact (Pd@MIL-101). The catalytic performance of Pd@MIL-101 in terms of activity and stability was demonstrated in the methanolysis of ammonia-borane (NH3BH3) under mild conditions (at 25 °C). We found that Pd@MIL-101 catalyst catalyzes the methanolysis of ammonia-borane at almost complete conversion (> 95%) with a turnover frequency value of 1748 h-1 at room temperature. Moreover, the resulting palladium nanoclusters were found to be highly stable against leaching and sintering, which makes Pd@MIL-101 reusable heterogeneous catalyst without losing of significant activity in the methanolysis of ammonia-borane.