Cu-based catalysts are widely employed for CO_(2) hydrogenation to methanol,which is expected as a promising process to achieving carbon neutrality.However,most Cu-based catalysts still suffer from low methanol yield ...Cu-based catalysts are widely employed for CO_(2) hydrogenation to methanol,which is expected as a promising process to achieving carbon neutrality.However,most Cu-based catalysts still suffer from low methanol yield with a passable CO_(2) conversion and lack insight into its reaction mechanism for guiding the design of catalysts.In this work,Cu^(+)/CeZrO_(x) interfaces are engineered by employing a series of ceria-zirconia solid solution catalysts with various Ce/Zr ratios,forming a Cu^(+)-O_(v)-Ce^(3+)structure where Cu^(+)atoms are bonded to the oxygen vacancies(O_(v))of ceria.Compared to Cu/CeO_(2) and Cu/ZrO_(2),the optimized catalyst(i.e.,Cu_(0.3)Ce_(0.3)Zr_(0.7))exhibits a much higher mass-specific methanol formation rate(192g_(MeOH)/kg_(cat)/h)at 240℃and 3 MPa.Through a series of in-situ and ex-situ characterization,it is revealed that oxygen vacancies in solid solutions can effectively assist the activation of CO_(2) and tune the electronic state of copper to promote the formation of Cu^(+)/CeZrO_(x) interfaces,which stabilizes the key*CO intermediate,inhibits its desorption and facilitates its further hydrogenation to methanol via the reverse watergas-shift(RWGS)+CO-Hydro pathway.Therefore,the concentration of*CO or the apparent Cu^(+)/(Cu^(+)+Cu^(0))ratio could be employed as a quantitative descriptor of the methanol formation rate.This work is expected to give a deep insight into the mechanism of metal/support interfaces in CO_(2) hydrogenation to methanol,offering an effective strategy to develop new catalysts with high performance.展开更多
Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological processes.Cu^(2+...Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological processes.Cu^(2+)binding to Aβ can promote the production of reactive oxygen species(ROS) through Fenton-like reactions and produce more toxic Aβ-Cu^(2+)species under Cu^(2+)stimulation. Thus, the development of nanomaterials that can inhibit Cu^(2+)-mediated Aβ aggregation and degrade Aβ-Cu^(2+)complexes is considered an effective strategy for the prevention and treatment of AD. In this study, polydopamine nanoparticles(PDA NPs) were prepared and the results reveal that PDA NPs potently inhibit Cu^(2+)-mediated Aβaggregation and effectively reduce the formation of Aβ-Cu^(2+)complexes. In vitro experiments show that PDA NPs efficiently eliminate ROS generation catalyzed by Cu^(2+)or Aβ-Cu^(2+)complexes, thus rescuing cultured cells by reducing intracellular ROS levels. More importantly, PDA NPs can depolymerize Aβ-Cu^(2+)complexes, and the degradation of Aβ-Cu^(2+)complexes is promoted by near-infrared light irradiation due to their high photothermal conversion ability. In vivo studies reveal that PDA NPs significantly reduce the deposition of Aβ plaques in the presence of Cu^(2+)and extend the lifespan of AD nematodes from 11 to 14 d. Thus, the PDA NPs developed herein are multifunctional against Cu^(2+)-mediated Aβ aggregation for the potential prevention and treatment of AD.展开更多
采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组...采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组分活度系数进行预测。结果表明:两个模型对含Cu^(2+)单电解质溶液活度系数的拟合效果均较好,eMIVM模型预测的拟合平均偏差和平均相对误差分别为0.0598和6.4%,eMIVM-ET模型预测的分别为0.0163和3.0%;对含Cu^(2+)的两电解质溶液的所有组分活度系数预测时,eMIVM-ET模型的预测效果要比eMIVM模型的好,eMIVM-ET模型预测时的平均偏差和平均相对误差分别为0.0844和18.2%;在含Cu^(2+)电解质溶液的热力学计算中,与eMIVM模型相比,eMIVM-ET模型更适合作为一个可供选择的预测模型。展开更多
基金sponsored by the National Natural Science Foundation of China(21808120,21978148)。
文摘Cu-based catalysts are widely employed for CO_(2) hydrogenation to methanol,which is expected as a promising process to achieving carbon neutrality.However,most Cu-based catalysts still suffer from low methanol yield with a passable CO_(2) conversion and lack insight into its reaction mechanism for guiding the design of catalysts.In this work,Cu^(+)/CeZrO_(x) interfaces are engineered by employing a series of ceria-zirconia solid solution catalysts with various Ce/Zr ratios,forming a Cu^(+)-O_(v)-Ce^(3+)structure where Cu^(+)atoms are bonded to the oxygen vacancies(O_(v))of ceria.Compared to Cu/CeO_(2) and Cu/ZrO_(2),the optimized catalyst(i.e.,Cu_(0.3)Ce_(0.3)Zr_(0.7))exhibits a much higher mass-specific methanol formation rate(192g_(MeOH)/kg_(cat)/h)at 240℃and 3 MPa.Through a series of in-situ and ex-situ characterization,it is revealed that oxygen vacancies in solid solutions can effectively assist the activation of CO_(2) and tune the electronic state of copper to promote the formation of Cu^(+)/CeZrO_(x) interfaces,which stabilizes the key*CO intermediate,inhibits its desorption and facilitates its further hydrogenation to methanol via the reverse watergas-shift(RWGS)+CO-Hydro pathway.Therefore,the concentration of*CO or the apparent Cu^(+)/(Cu^(+)+Cu^(0))ratio could be employed as a quantitative descriptor of the methanol formation rate.This work is expected to give a deep insight into the mechanism of metal/support interfaces in CO_(2) hydrogenation to methanol,offering an effective strategy to develop new catalysts with high performance.
基金funded by the National Natural Science Foundation of China (21978207 and 21621004)the Natural Science Foundation of Tianjin from Tianjin Municipal Science and Technology Commission (19JCZDJC36800)。
文摘Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological processes.Cu^(2+)binding to Aβ can promote the production of reactive oxygen species(ROS) through Fenton-like reactions and produce more toxic Aβ-Cu^(2+)species under Cu^(2+)stimulation. Thus, the development of nanomaterials that can inhibit Cu^(2+)-mediated Aβ aggregation and degrade Aβ-Cu^(2+)complexes is considered an effective strategy for the prevention and treatment of AD. In this study, polydopamine nanoparticles(PDA NPs) were prepared and the results reveal that PDA NPs potently inhibit Cu^(2+)-mediated Aβaggregation and effectively reduce the formation of Aβ-Cu^(2+)complexes. In vitro experiments show that PDA NPs efficiently eliminate ROS generation catalyzed by Cu^(2+)or Aβ-Cu^(2+)complexes, thus rescuing cultured cells by reducing intracellular ROS levels. More importantly, PDA NPs can depolymerize Aβ-Cu^(2+)complexes, and the degradation of Aβ-Cu^(2+)complexes is promoted by near-infrared light irradiation due to their high photothermal conversion ability. In vivo studies reveal that PDA NPs significantly reduce the deposition of Aβ plaques in the presence of Cu^(2+)and extend the lifespan of AD nematodes from 11 to 14 d. Thus, the PDA NPs developed herein are multifunctional against Cu^(2+)-mediated Aβ aggregation for the potential prevention and treatment of AD.
文摘采用电解质分子相互作用体积模型eMIVM(Electrolyte Molecular Interaction Volume Model)与它的能量项eMIVM-ET(Energy term of eMIVM)分别对含Cu^(2+)的20个单电解质溶液的活度系数进行拟合,并对含Cu^(2+)的5个两电解质溶液的所有组分活度系数进行预测。结果表明:两个模型对含Cu^(2+)单电解质溶液活度系数的拟合效果均较好,eMIVM模型预测的拟合平均偏差和平均相对误差分别为0.0598和6.4%,eMIVM-ET模型预测的分别为0.0163和3.0%;对含Cu^(2+)的两电解质溶液的所有组分活度系数预测时,eMIVM-ET模型的预测效果要比eMIVM模型的好,eMIVM-ET模型预测时的平均偏差和平均相对误差分别为0.0844和18.2%;在含Cu^(2+)电解质溶液的热力学计算中,与eMIVM模型相比,eMIVM-ET模型更适合作为一个可供选择的预测模型。
