Lanthanum-Doped Ceria Nanocomposite: A Highly Stable Monolithic Catalyst for Direct Synthesis of Dimethyl Carbonate

Abstract

That dimethyl carbonate is directly synthesized from methanol and carbon dioxide is an effective and environmental approach to solve the greenhouse effect. For the sake of solving the problems of low DMC productivity and poor catalysts stability in presence of the formed water. Here we design and prepare a serial of spherical La-doped ceria nanoparticles (Ce 1-x La x O δ nanocomposites, x=0.00, 0.05, 0.10, 0.15, and 0.20) via a co-precipitation method. These Ce 1-x La x O δ composites are ground into slurry by ball milled and then coated on cordierite honeycomb ceramics to obtain Ce 1-x La x O δ monolithic catalysts. These Ce 1-x La x O δ composites are characterized extensively by TEM, XRD, Raman spectroscopy, N 2 adsorption-desorption isotherms, H 2 -TPR and XPS. The characterization results show that the Ce 1-x La x O δ composites nanoparticles possesses richer surface oxygen vacancies, higher BET surface area and smaller particle size than that of pure CeO 2 nanoparticle. Besides, catalytic activity test shows these Ce 1-x La x O δ monolithic catalysts exhibit better catalytic performance than that of pure CeO 2 nanoparticles. Among them, Ce 0.95 La 0.05 O δ monolithic catalyst exhibits the highest CH 3 OH conversion and DMC yield, which is in good line with the oxygen vacancy content measured by XPS. Finally, the Ce 0.95 La 0.05 O δ monolithic catalyst also shows an excellent durability of more than 100 hours, which is mainly due to the doping effect of lanthanum into the ceria oxides tailoring the structure and surface properties of the catalyst.