A Novel Route to the Preparation of Carbon Supported Nickel Phosphide Catalysts by a Microwave Heating Process

A simple and efficient approach based on microwave heating process was developed to prepare carbon supported nickel phosphide. In this approach, red phosphorus was used as a P source and carbon acted as both the support and the microwave absorbent. The red phosphorus was homogeneously mixed with Ni-impregnated carbon by milling, and then subjected to microwave heating. After several minutes by microwave heating in Ar or H-2 atmosphere, the nickel phosphide, Ni2P, was produced on the carbon support, while the temperature of the sample bed was only 473 K or even lower during the reaction. It was also found that the preparation atmosphere had significant effects on the phosphide formation. Compared to the preparation in Ar, the nickel phosphides prepared in H2 were more readily formed and more highly dispersed on the carbon support due to PH3 formation during the reduction process. The as-prepared nickel phosphide catalysts exhibited much higher activities in selective hydrogenation of 1,3-butadiene compared to that prepared by the conventional heating method, which was attributed to the high dispersion of Ni2P prepared by the microwave heating method.