Based on the concept of intercalation chemistry of layered double hydroxides (LDHs), RhCl(CO)- (TPPTS)2 (TPPTS: P(m-C6H4SO3Na)3) and TPPTS co-intercalated LDHs were successfully synthesized by in situ complexation method. Characterizations of structure and composition of composite materials by powder XRD, FT-IR, and ICP-AES techniques confirmed the supramolecular structures of the catalytic species intercalated LDHs. The correlation between catalytic performance of intercalated catalyst and the composition of both host layers and interlayer guest species was also investigated.
Spherical mesoporous ZrO_(2)-Al_(2)O_(3) composites containing different zirconia content have been synthesized by an oil-column sol-gel method.A mixed alumina-zirconia hydrosol and hexamethylenetetramine solution were mixed together and added dropwise into a hot oil column.Due to the surface tension,spherical gel particles were formed in the oil column.The spherical gel particles were then aged and washed by deionized water and dried at 120 ℃ for 12 h and then calcined at 600 ℃ for 8 h,960 ℃ for 8 h or 1200 ℃ for 12 h.X-ray diffraction and nitrogen adsorption-desorption measurements indicated that the presence of zirconia prevents the sintering of alumina and the obtained ZrO_(2)-Al_(2)O_(3) composites have much larger surface areas than pure alumina.Temperature-programmed desorption of ammonia results illustrated that the addition of zirconia leads to an increase in the number of strong acid sites and the total number of acid sites compared with pure alumina.Thus,the spherical mesoporous ZrO_(2)-Al_(2)O_(3) composites prepared in this way were shown to be suitable for high temperature catalytic processes as a catalyst support.
Cathode materials Li[Co x Ni y Mn 1-x-y ]O 2 for lithium secondary batteries have been prepared by a new route using layered double hydroxides (LDHs) as a precursor. The resulting layered phase with the - NaFeO 2 structure crystallizes in the rhombohedral system, with space group R-3m having an interlayer spacing close to 0.47 nm. X-ray photoelectron spectroscopy (XPS) was used to measure the oxidation states of Co, Ni and Mn. The effects of varying the Co/Ni/Mn ratio on both the structure and electrochemical properties of Li[Co x Ni y Mn 1-x-y ]O 2 have been investigated by X-ray diffraction and electrochemical tests. The products demonstrated a rather stable cycling behavior, with a reversible capacity of 118 mAh/g for the layered material with Co/Ni/Mn = 1/1/1.
