porous aluminum phosphate;  nitriding;  aluminum nitride phosphate;  preparation;  First-order kinetic equations

A new catalytic material aluminum nitride phosphate was prepared by reacting with ammonia at a high temperature of about 800 °C by reacting amorphous aluminum phosphate at a high temperature of about 0 °C. The effects of aluminum phosphate particle size, ammonia flow rate and nitriding temperature on the preparation were investigated. Experiments have found that the particle size of the material has a certain influence on nitriding, and this effect disappears when the particle size is less than 25.800mm.The nitriding process requires a large ammonia flow rate to ensure a faster nitriding rate. When the ammonia flow is low, the reaction speed is too slow and the nitriding time is very long. The nitriding rate accelerates with the increase of nitriding temperature. The experiment also found that there was a significant loss of phosphorus in nitriding at 5°C, and the nitriding began to decrease from 1 to about 0.75 at <> h, and then remained constant. A first-order epikinetic equation describing the change of nitrogen content of samples with nitriding time during nitriding was established, which could fit the experimental data well.