Synthesis of Zn-Al LDHs intercalated with urea derived anions for capturing carbon dioxide from natural gas

Abstract

Zinc-aluminum layered double hydroxides (Zn-Al LDHs) with different Zn/Al ratios (Zn/Al = 6, 3 and 2) were prepared using a homogenous precipitation method by urea hydrolysis. The preparation was performed at various temperatures (70-100 °C). The element chemical analysis, X-ray powder diffraction and Fourier transform infrared spectra show that urea species and cyanate anions are the main anions intercalated at low temperature and low Zn/Al ratios. This was confirmed by pH curves recorded during the reaction, thermal analyses, temperature programmed desorption. The presence of intercalated urea and cyanate species creates UV absorption activities for the ZA15-80 and ZA35-80 samples and enhance the selectivity of ZA15-80 toward the adsorption of carbon dioxide from natural gas. © 2013 Taiwan Institute of Chemical Engineers.