Preparation of mesoporous nanocrystalline cerium phosphate with controllable pore size by using chelating agent

A considerably high surface area of nanocrystalline mesoporous cerium phosphate with controllable pore size has been obtained by using N-(2-hydroxyethyl)-ethylenediane-N,N′,N′-triacetic acid (H3hedtra) as chelating agent. By varying the mole ratio of H3hedtra/Ce during synthesis, the surface area and average pore size of the materials as well as narrow pore size distribution can be controlled properly. The highest surface area of the obtained cerium phosphate is 145 m2 g−1 with average pore size at 8.54 nm, which is significantly higher than that of the reference sample prepared without H3hedtra. The morphology of the samples was observed by using TEM where sample prepared in the presence of H3hedtra possessed relatively smaller particle size compared with the reference sample prepared without H3hedtra. Besides, higher amount of acidic sites was found for samples prepared in the presence of H3hedtra compared with the sample prepared free of H3hedtra. Although the acid strength remained unchanged, the surface concentration of acidic sites had increased at mole ratio of H3hedtra/Ce above 0.5.