MOF Derived Non-Noble Metal Based Nanocatalyst for the Selective Reduction of 4-Nitrophenol

Abstract

Recently research on heterogeneous catalyst derived from metal organic frameworks has become the subject of immense interest due to their significant bifunctional, physical, chemical and magnetic properties as compared to original MOFs. This work represents the engineering of nanostructures using one-step annealing method. The Fe-MOF precursor was formed by the association of FeCl3.6H2O and 1,4-dicarboxylic acid through using simple solvothermal method. The annealing of MOF at different temperatures (400oC, 600oC, 800oC) under inert atmosphere precisely synthesized three catalysts Fe/C-400, Fe/C600, Fe/C800 respectively with large surface area, morphology and tunable porosity. Nanometer size iron, iron oxide nanoparticles formed and uniformly dispersed over the graphitic carbon. The prepared nanostructures were characterized by various analytical techniques including FTIR, XRD, TGA, SEM, TEM, EDS and XPS. XPS and TEM results confirmed the formation of zero valent iron at 800oC that exhibit nano-ropes like morphology with average diameter of about 10nm. These catalysts were tested for the selective reduction of 4-Nitrophenol. The results of catalytic reduction showed that the Fe/C-800 catalyst exhibit excellent catalytic activity with the apparent rate constant value 0.0149s-1 at 0.4mg Nanoparticle loading. This non-noble metal catalyst showed better or comparable catalytic activity than many reported precious metal catalyst. Loading of catalyst and annealing temperature significantly affect the catalytic activity. This study will pave the way for the application in heterogeneous catalysis of diversity of substrates and use of these materials on large scale.