2 research outputs found
TiO<sub>2</sub>‑Doped CeO<sub>2</sub> Nanorod Catalyst for Direct Conversion of CO<sub>2</sub> and CH<sub>3</sub>OH to Dimethyl Carbonate: Catalytic Performance and Kinetic Study
A new
class of TiO<sub>2</sub>-doped CeO<sub>2</sub> nanorods was
synthesized via a modified hydrothermal method, and these nanorods
were first used as catalysts for the direct synthesis of dimethyl
carbonate (DMC) from CO<sub>2</sub> and CH<sub>3</sub>OH in a fixed-bed
reactor. The micromorphologies and physical–chemical properties
of nanorods were characterized by transmission electron microscopy,
X-ray diffraction, N<sub>2</sub> adsorption, inductively coupled plasma
atomic emission spectrometry, X-ray photoelectron spectroscopy, and
temperature-programmed desorption of ammonia and carbon dioxide (NH<sub>3</sub>-TPD and CO<sub>2</sub>-TPD). The effects of the TiO<sub>2</sub> doping ratio on the catalytic performances were fully investigated.
By doping TiO<sub>2</sub>, the surface acid–base sites of CeO<sub>2</sub> nanorods can be obviously promoted and the catalytic activity
can be raised evidently. Ti<sub>0.04</sub>Ce<sub>0.96</sub>O<sub>2</sub> nanorod catalysts exhibited remarkably high activity with a methanol
conversion of 5.38% with DMC selectivity of 83.1%. Furthermore, kinetic
and mechanistic investigations based on the initial rate method were
conducted. Over the Ti<sub>0.04</sub>Ce<sub>0.96</sub>O<sub>2</sub> nanorod catalyst, the apparent activation energy of the reaction
was 46.3 kJ/mol. The reaction rate law was determined to be of positive
first-order to the CO<sub>2</sub> concentration and the catalyst loading
amount. These results were practically identical with the prediction
of the Langmuir–Hinshelwood mechanism in which the steps of
CO<sub>2</sub> adsorption and activation are considered as rate-determining
steps
TiO<sub>2</sub>‑Doped CeO<sub>2</sub> Nanorod Catalyst for Direct Conversion of CO<sub>2</sub> and CH<sub>3</sub>OH to Dimethyl Carbonate: Catalytic Performance and Kinetic Study
A new
class of TiO<sub>2</sub>-doped CeO<sub>2</sub> nanorods was
synthesized via a modified hydrothermal method, and these nanorods
were first used as catalysts for the direct synthesis of dimethyl
carbonate (DMC) from CO<sub>2</sub> and CH<sub>3</sub>OH in a fixed-bed
reactor. The micromorphologies and physical–chemical properties
of nanorods were characterized by transmission electron microscopy,
X-ray diffraction, N<sub>2</sub> adsorption, inductively coupled plasma
atomic emission spectrometry, X-ray photoelectron spectroscopy, and
temperature-programmed desorption of ammonia and carbon dioxide (NH<sub>3</sub>-TPD and CO<sub>2</sub>-TPD). The effects of the TiO<sub>2</sub> doping ratio on the catalytic performances were fully investigated.
By doping TiO<sub>2</sub>, the surface acid–base sites of CeO<sub>2</sub> nanorods can be obviously promoted and the catalytic activity
can be raised evidently. Ti<sub>0.04</sub>Ce<sub>0.96</sub>O<sub>2</sub> nanorod catalysts exhibited remarkably high activity with a methanol
conversion of 5.38% with DMC selectivity of 83.1%. Furthermore, kinetic
and mechanistic investigations based on the initial rate method were
conducted. Over the Ti<sub>0.04</sub>Ce<sub>0.96</sub>O<sub>2</sub> nanorod catalyst, the apparent activation energy of the reaction
was 46.3 kJ/mol. The reaction rate law was determined to be of positive
first-order to the CO<sub>2</sub> concentration and the catalyst loading
amount. These results were practically identical with the prediction
of the Langmuir–Hinshelwood mechanism in which the steps of
CO<sub>2</sub> adsorption and activation are considered as rate-determining
steps