Catalytic reduction of 4-nitrophenol using copper terephthalate frameworks and CuO@C composite

Two-dimensional (2D) metal-organic frameworks (MOFs), called copper-terephthalate, and CuO@C were investigated as catalysts for the reduction of 4-nitrophenol (4-NP) via hydrogenation using sodium borohydride (NaBH4) as a reducing agent. Copper-terephthalate frameworks were synthesized using the solvothermal method. While, CuO@C was synthesized using carbonization of copper-terephthalate at temperature of 400 degrees C, 500 degrees C, 600 degrees C, and 700 degrees C. Both materials displayed a complete reduction of 4-NP to 4-aminophenol (4-AP) in a short time (3 min) with a rate of 15.1x10(-3) min(-1), and 6.0x10(-3) min(-1) at room temperature for CuBDC, and CuO@C, respectively. The materials could be used for more than five times without obvious fading in their catalytic activities. The mechanism of the reduction was also discussed. The materials are promising for catalytic applications such as organic synthesis via the reduction of the nitro groups.