Thermal Activation of CuBTC MOF for CO Oxidation: The Effect of Activation Atmosphere

High performance catalysts for carbon monoxide (CO) oxidation were obtained through thermal activation of a CuBTC (BTC: 1,3,5-benzenetricarboxylic acid) metal-organic framework (MOF) in various atmospheres. X-ray diffraction (XRD), X-ray photonelectron spectroscopy (XPS), N2 adsorption-desorption measurement, and field emission scanning electron microscopy (FESEM) were adopted to characterize the catalysts. The results show that thermal activation by reductive H2 may greatly destroy the structure of CuBTC. Inert Ar gas has a weak influence on the structure of CuBTC. Therefore, these two catalysts exhibit low CO oxidation activity. Activating with O2 is effective for CuBTC catalysts, since active CuO species may be obtained due to the slight collapse of CuBTC structure. The highest activity is obtained when activating with CO reaction gas, since many pores and more effective Cu2O is formed during the thermal activation process. These results show that the structure and chemical state of coordinated metallic ions in MOFs are adjustable by controlling the activation conditions. This work provides an effective method for designing and fabricating high performance catalysts for CO oxidation based on MOFs.