The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,an...The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,and the catalysts were characterized. Temperature program desorption （TPD） experiments or toluene and water on the catalysts were carried out. The influence of water vapor on the activity of the catalysts was discussed. Results showed that addition of the water vapor has a significant negative effect on the catalytic activity of the catalysts.The higher the concentration of the Water vapor in feed steam was, the lower the catalytic activity of the copper based catalysts became, which could be mainly ascribed to the competition of water molecules with toluene molecules for adsorption on the catalyst surfaces. TPD experiments showed that the strength of the interaction between water molecules and three catalysts followed the order： CuO/γ-Al2O3〉CuO/γ-Al2O3-Cord〉CuO/Cord. As a consequence of that, the degree of degradation in the catalytic activity of these three catalysts by the water vapor followed the order： CuO/γ-Al2O3〉CuO/y-Al2O3-Cord〉CuO/Cord. However, the negative effect of the water vapor was reversible.展开更多
The catalytic activity for the synthesis of methanol from carbon dioxide and hydrogen was measured on various binary and ternary catalysts containing copper oxide under a pressure of 10 atm. Among these samples the ca...The catalytic activity for the synthesis of methanol from carbon dioxide and hydrogen was measured on various binary and ternary catalysts containing copper oxide under a pressure of 10 atm. Among these samples the catalysts, CuO/ZnO/γ-Al_2O_3, demonstrated the highest activity and selectivity to methanol; MnO, as third component, had no promotional effect on the activity of meth- anol formation. Based on a simple power rate law the apparent activation energy estimation and par- tial pressure dependence measurement were accomplished over eight catalysts. The activation energies varied from 40 to 120 kJ / mol depending on the composition of catalysts. The rates of methanol for- mation to be 0.3 -- 0.9 order in H_2 and about 0.1 -- 0.2 order in CO_2 were reported.展开更多
Nitrogen is essential for life and ecosystems.The nitrogen cycle is fundamental to all life on earth and has been implicated in his-torical mass extinction events,where disruptions to its stability have played a criti...Nitrogen is essential for life and ecosystems.The nitrogen cycle is fundamental to all life on earth and has been implicated in his-torical mass extinction events,where disruptions to its stability have played a critical role[1].Moreover,the nitrogen cycle's response to climate change could critically influence atmo-spheric CO_(2) levels and the trajectory of global warming[2].However,improper management of anthropogenic nitrogen-containing wastewater,including domestic sewage,agricultural runoff,and industrial effluents,has pushed the nitrogen cycle to the brink of imbalance[1].展开更多
基金Supported by the National-Natural Science Foundation of China （20936001）, the Natural Science Foundation of Guangdong Province, and the State Key Lab of Subtropical Building Science, South China University of Technology （x2yj C709028Z）.
文摘The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,and the catalysts were characterized. Temperature program desorption （TPD） experiments or toluene and water on the catalysts were carried out. The influence of water vapor on the activity of the catalysts was discussed. Results showed that addition of the water vapor has a significant negative effect on the catalytic activity of the catalysts.The higher the concentration of the Water vapor in feed steam was, the lower the catalytic activity of the copper based catalysts became, which could be mainly ascribed to the competition of water molecules with toluene molecules for adsorption on the catalyst surfaces. TPD experiments showed that the strength of the interaction between water molecules and three catalysts followed the order： CuO/γ-Al2O3〉CuO/γ-Al2O3-Cord〉CuO/Cord. As a consequence of that, the degree of degradation in the catalytic activity of these three catalysts by the water vapor followed the order： CuO/γ-Al2O3〉CuO/y-Al2O3-Cord〉CuO/Cord. However, the negative effect of the water vapor was reversible.
基金Work financially supported by the National Natural Science Foundation of China.
文摘The catalytic activity for the synthesis of methanol from carbon dioxide and hydrogen was measured on various binary and ternary catalysts containing copper oxide under a pressure of 10 atm. Among these samples the catalysts, CuO/ZnO/γ-Al_2O_3, demonstrated the highest activity and selectivity to methanol; MnO, as third component, had no promotional effect on the activity of meth- anol formation. Based on a simple power rate law the apparent activation energy estimation and par- tial pressure dependence measurement were accomplished over eight catalysts. The activation energies varied from 40 to 120 kJ / mol depending on the composition of catalysts. The rates of methanol for- mation to be 0.3 -- 0.9 order in H_2 and about 0.1 -- 0.2 order in CO_2 were reported.
基金supported by the National Natural Science Foundation of China(Nos.52172291,52122312 and 52473294)the“Shuguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.22SG31).
文摘Nitrogen is essential for life and ecosystems.The nitrogen cycle is fundamental to all life on earth and has been implicated in his-torical mass extinction events,where disruptions to its stability have played a critical role[1].Moreover,the nitrogen cycle's response to climate change could critically influence atmo-spheric CO_(2) levels and the trajectory of global warming[2].However,improper management of anthropogenic nitrogen-containing wastewater,including domestic sewage,agricultural runoff,and industrial effluents,has pushed the nitrogen cycle to the brink of imbalance[1].
