Effect of Activation Temperature on Properties of H3PO4-Activated Carbon

The effects of different activation temperatures (Ta), ranging from 300 to 750 degrees C, on the ash content, yield, ignition point, microcrystalline structure, surface functional group, pore structure, and adsorption performance of activated carbon in preparing activated carbon by phosphoric acid (H3PO4) were systematically studied. The yield and volatile content of activated carbon decreased with the increase of Ta, while the ash content, ignition point, and graphitization degree showed the opposite results. The turning point of ash content increasing rate of activated carbon occurred at 500 degrees C. The thermal decomposition temperature of phosphonate compounds was approximately 450 degrees C. With increased Ta, micropores were generated first, followed by mesopores. The ignition point of activated carbon was related to the volatile content and the degree of graphitization. Activated carbon with low ash content, high yield, well-developed pore structure and good adsorption performance was prepared at 350 to 425 degrees C. With increased Ta, the volatile content decreased, and the ignition point of activated carbon increased. At Ta higher than 500 degrees C, the aromatic and condensed ring structure, graphitization degree, and mesopore ratio of the activated carbon increased, yielding decreased adsorption performance.

Automated summary

The effects of different activation temperatures on preparing activated carbon by phosphoric acid were systematically studied, showing that activated carbon prepared at 350 to 425 degrees Celsius had excellent performance, while higher temperatures resulted in decreased adsorption performance.