Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among t...Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among the most promising candidates for this application,the relationship between Ni coordination structure and catalytic properties is still under strong debate.Here,we fabricated a series of Ni SACs through precise-engineering of anchor sites on nitrogen-doped carbon(NC)followed by Ni atom anchoring using atomic layer deposition.Among them,a Ni_(1)/NC SAC,with a coordination number(CN)of four but less pyridinic nitrogen(N_(pyri)),achieved over 90%faradaic efϐiciency for CO at potentials from-0.7 to-1.0 V and a mass activity of 6.5 A/mgNi at-0.78 V along with high stability,outperforming other Ni SACs with lower CN and more N_(pyri).Theoretical calculations of various three and four-coordinated Ni_(1)-NxCy structures revealed a linear correlation between the reaction Gibbs free energy for the potential-limiting step and the highest occupied molecular orbital(HOMO)position of Ni-3d orbitals,therein the four-coordinated Ni_(1)-N_(1)C_(3)with the highest HOMO position is identified as the active site for the electrocatalytic CO_(2)-to-CO process,in line with the experimental results.展开更多
Aseptic prosthesis loosening(APL)is one of the most prevalent complications associated with arthroplasty.The main cause is the periprosthetic osteolysis induced by wear particles.However,the specific mechanisms of cro...Aseptic prosthesis loosening(APL)is one of the most prevalent complications associated with arthroplasty.The main cause is the periprosthetic osteolysis induced by wear particles.However,the specific mechanisms of crosstalk between immune cells and osteoclasts/osteoblasts during osteolysis are unclear.In this study,we report the role and mechanism of macrophage-derived exosomes in wear particle-induced osteolysis.The results of exosomes up-taken experiments revealed that osteoblast and mature osteoclasts capture macrophage-derived exosomes(M-Exo).Next-generation sequencing and RT-qPCR on M-Exo revealed that exosomal microRNA miR-3470b was downregulated in wear particle-induced osteolysis.The results of analysis on Luciferase reporter assays/fluorescence in situ hybridization(FISH)/immunofluorescence(IF)/immunohistochemistry(IHC)and co-culture experiments demonstrated that wear particles induced osteoclast differentiation by increasing the expression of NFatc1 via M-Exo miR-3470b targeting TAB3/NF-κB signaling.We also illustrate that engineered exosomes enriching miR-3470b facilitated to suppressed the osteolysis;the microenvironment enriching with miR-3470b could suppress wear particle-induced osteolysis via inhibition of TAB3/NF-κB in vivo.In summary,our findings indicate that macrophage-derived exosomes transfer to osteoclasts to induce osteolysis in wear particle-induced APL.Engineering exosomes enriching with miR-3470b might be a novel strategy for the targeting treatment of bone resorption-related diseases.展开更多
Propane dehydrogenation(PDH),an atom-economic reaction to produce high-value-added propylene and hydrogen with high efficiency,has recently attracted extensive attention.The severe deactivation of Pt-based catalysts t...Propane dehydrogenation(PDH),an atom-economic reaction to produce high-value-added propylene and hydrogen with high efficiency,has recently attracted extensive attention.The severe deactivation of Pt-based catalysts through sintering and coking remains a major challenge in this high-temperature reaction.The introduction of Sn as a promoter has been widely applied to improve the stability and selectivity of the catalysts.However,the selectivity and stability of PtSn catalysts have been found to vary considerably with synthesis methods,and the role of Sn is still far from fully understanding.To gain in-depth insights into this issue,we synthesized a series of PtSn/SiO_(2)and SnPt/SiO_(2)catalysts by varying the deposition sequence and Pt:Sn ratios using atomic layer deposition with precise control.We found that PtSn/SiO_(2)catalysts fabricated by the deposition of SnO_(x)first and then Pt,exhibited much better propylene selectivity and stability than the SnPt/SiO_(2)catalysts synthesized the other way around.We demonstrate that the presence of Sn species at the Pt-SiO_(2)interface is of essential importance for not only the stabilization of PtSn clusters against sintering under reaction conditions but also the promotion of charge transfers to Pt for high selectivity.Besides the above,the precise regulation of the Sn content is also pivotal for high performance,and the excess amount of Sn might generate additional acidic sites,which could decrease the propylene selectivity and lead to heavy coke formation.These findings provide deep insight into the design of highly selective and stable PDH catalysts.展开更多
文摘Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among the most promising candidates for this application,the relationship between Ni coordination structure and catalytic properties is still under strong debate.Here,we fabricated a series of Ni SACs through precise-engineering of anchor sites on nitrogen-doped carbon(NC)followed by Ni atom anchoring using atomic layer deposition.Among them,a Ni_(1)/NC SAC,with a coordination number(CN)of four but less pyridinic nitrogen(N_(pyri)),achieved over 90%faradaic efϐiciency for CO at potentials from-0.7 to-1.0 V and a mass activity of 6.5 A/mgNi at-0.78 V along with high stability,outperforming other Ni SACs with lower CN and more N_(pyri).Theoretical calculations of various three and four-coordinated Ni_(1)-NxCy structures revealed a linear correlation between the reaction Gibbs free energy for the potential-limiting step and the highest occupied molecular orbital(HOMO)position of Ni-3d orbitals,therein the four-coordinated Ni_(1)-N_(1)C_(3)with the highest HOMO position is identified as the active site for the electrocatalytic CO_(2)-to-CO process,in line with the experimental results.
基金supported by the National Natural Science Foundation of China[grant numbers 82172405,81972050,81802179].
文摘Aseptic prosthesis loosening(APL)is one of the most prevalent complications associated with arthroplasty.The main cause is the periprosthetic osteolysis induced by wear particles.However,the specific mechanisms of crosstalk between immune cells and osteoclasts/osteoblasts during osteolysis are unclear.In this study,we report the role and mechanism of macrophage-derived exosomes in wear particle-induced osteolysis.The results of exosomes up-taken experiments revealed that osteoblast and mature osteoclasts capture macrophage-derived exosomes(M-Exo).Next-generation sequencing and RT-qPCR on M-Exo revealed that exosomal microRNA miR-3470b was downregulated in wear particle-induced osteolysis.The results of analysis on Luciferase reporter assays/fluorescence in situ hybridization(FISH)/immunofluorescence(IF)/immunohistochemistry(IHC)and co-culture experiments demonstrated that wear particles induced osteoclast differentiation by increasing the expression of NFatc1 via M-Exo miR-3470b targeting TAB3/NF-κB signaling.We also illustrate that engineered exosomes enriching miR-3470b facilitated to suppressed the osteolysis;the microenvironment enriching with miR-3470b could suppress wear particle-induced osteolysis via inhibition of TAB3/NF-κB in vivo.In summary,our findings indicate that macrophage-derived exosomes transfer to osteoclasts to induce osteolysis in wear particle-induced APL.Engineering exosomes enriching with miR-3470b might be a novel strategy for the targeting treatment of bone resorption-related diseases.
基金supported by the National Natural Science Foundation of China(22102168)the National Science Fund for Distinguished Young Scholars(22025205)+4 种基金the Anhui Natural Science Foundation of China(2108085QB59)Project funded by the China Postdoctoral Science Foundation(BX20190312,2020M671867)the University of Science and Technology of China Youth Innovation Key Fund(YD9990002015)the Fundamental Research Funds for the Central Universities(WK2060000038,WK3430000005)the National Synchrotron Radiation Laboratory(KY2340000135).
文摘Propane dehydrogenation(PDH),an atom-economic reaction to produce high-value-added propylene and hydrogen with high efficiency,has recently attracted extensive attention.The severe deactivation of Pt-based catalysts through sintering and coking remains a major challenge in this high-temperature reaction.The introduction of Sn as a promoter has been widely applied to improve the stability and selectivity of the catalysts.However,the selectivity and stability of PtSn catalysts have been found to vary considerably with synthesis methods,and the role of Sn is still far from fully understanding.To gain in-depth insights into this issue,we synthesized a series of PtSn/SiO_(2)and SnPt/SiO_(2)catalysts by varying the deposition sequence and Pt:Sn ratios using atomic layer deposition with precise control.We found that PtSn/SiO_(2)catalysts fabricated by the deposition of SnO_(x)first and then Pt,exhibited much better propylene selectivity and stability than the SnPt/SiO_(2)catalysts synthesized the other way around.We demonstrate that the presence of Sn species at the Pt-SiO_(2)interface is of essential importance for not only the stabilization of PtSn clusters against sintering under reaction conditions but also the promotion of charge transfers to Pt for high selectivity.Besides the above,the precise regulation of the Sn content is also pivotal for high performance,and the excess amount of Sn might generate additional acidic sites,which could decrease the propylene selectivity and lead to heavy coke formation.These findings provide deep insight into the design of highly selective and stable PDH catalysts.
