Controllable Synthesis of Pd-ZIF-L-GO: The Role of Drying Temperature

The design and synthesis of metal-organic framework/graphene oxide (MOF/GO) composites are vital for their applications in energy, adsorption, sensing, supercapacitors, and catalysis. How to achieve high-performance MOF/GO composites still remains a great challenge. Herein, a simple strategy is proposed by adjusting the drying temperature to regulate the structural properties of Pd-ZIF-L-GO catalysts (Pd/ZG-X, where X indicates the drying temperature in vacuum and ZIF refers to the zeolitic imidazolate framework - a subclass of the MOF) and their catalytic performance in the reduction of nitroarenes. The as-prepared Pd/ZG-150 catalyst has high specific surface area, high degree of defects, small Pd particle size, and high pyrrolic N content, contributing to the highest catalytic activity with 100% conversion of p-nitrophenol (4-NP) to p-aminophenol (4-AP), which is 1.4 times higher than that of Pd/ZG-50. Pd/ZG-150 has good reusability during six reaction cycles. Furthermore, Pd/ZG-150 also exhibits the highest catalytic activity in the hydrogenation of o-nitrophenol, p-nitrobenzoic acid, and p-nitrotoluene. These findings will aid the development of high-performance MOF/GO composites.