Catalysts preparation
The fresh chicken manure collected was firstly dried under the sunlight for several days or until it is dried. The dried chicken manure was then ground to fine power. After that, the power sample was calcined under air for 4 h at high calcination temperatures ranging from 550 to 950 C (with a heating rate of 2 C/min).
The solid resultant was then ground, sieved, and kept in a desiccator.