Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors (i.e., pressure and temperat...Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors (i.e., pressure and temperature) were investigated to explore the effects of catalyst structure and physic-chemical properties (i.e., morphology, reducing property, oxygen storage capacity and specific surface area). The resulting materials were characterized with X-ray diffraction (XRD), high resolution transmission electron micros-copy (HRTEM), Brunauer-Emmett-Teller (BET),hydrogen temperature programmed reduction (H2-TPR) and oxygen storage capac-ity (OSC) measurement, respectively. The experimental results showed that lower temperatures promoted production of hollow struc-ture nano-particulates. The particle morphology also changed significantly, i.e. the solid construction was first transferred to hollow structure then back to solid construction. The optimal conditions for obtaining hollow nano-particles were determined at 45 °C, 18.0–24.0 MPa.展开更多
The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support,...The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one (ZrO2-1) was obtained from the commercial ZrO2 and the other (ZrO2-2) was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.展开更多
基金supported by the National Natural Science Foundation of China(20976120)Natural Science Foundation of Tianjin(09JCYBJC06200)
摘要Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors (i.e., pressure and temperature) were investigated to explore the effects of catalyst structure and physic-chemical properties (i.e., morphology, reducing property, oxygen storage capacity and specific surface area). The resulting materials were characterized with X-ray diffraction (XRD), high resolution transmission electron micros-copy (HRTEM), Brunauer-Emmett-Teller (BET),hydrogen temperature programmed reduction (H2-TPR) and oxygen storage capac-ity (OSC) measurement, respectively. The experimental results showed that lower temperatures promoted production of hollow struc-ture nano-particulates. The particle morphology also changed significantly, i.e. the solid construction was first transferred to hollow structure then back to solid construction. The optimal conditions for obtaining hollow nano-particles were determined at 45 °C, 18.0–24.0 MPa.
摘要The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one (ZrO2-1) was obtained from the commercial ZrO2 and the other (ZrO2-2) was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.