Promotional Effects of Ni and Mg on the Preferential Oxidation of CO over Carbon Nanotube-Supported Pt Catalyst

A carbon nanotube-supported Pt catalyst promoted by Ni and Mg (Pt-Ni-Mg/CNT) was prepared by the co-impregnation method for preferential oxidation of CO in H-2-rich gas. The results of X-ray diffraction, H-2 temperature-programmed reduction, transmission electron microscopy, and energy dispersive spectroscopy indicated that Pt interacted with Ni and Mg on CNT surface and might form alloy nanoparticles to some extents, which in turn markedly improved the catalytic performance of preferential oxidation of CO in H-2-rich gas. The results of performance tests showed that CO conversion at low temperatures could be effectively enhanced by adding a proper amount of Ni, while the selectivity was improved by adding a proper amount of Mg. When Ni and Mg were added simultaneously, the 5%Pt-5%Ni-5%Mg/CNT catalyst showed CO conversion of 100% and selectivity for CO2 of 53.7% in a H-2-rich stream at 100 degrees C. The catalytic performance did not change obviously during 24 h of ran at 140 degrees C