A growing body of evidence suggests that the gut microbiota contributes to the development of neurodegenerative diseases via the microbiota-gut-brain axis.As a contributing factor,microbiota dysbiosis always occurs in...A growing body of evidence suggests that the gut microbiota contributes to the development of neurodegenerative diseases via the microbiota-gut-brain axis.As a contributing factor,microbiota dysbiosis always occurs in pathological changes of neurodegenerative diseases,such as Alzheimer’s disease,Parkinson’s disease,and amyotrophic lateral sclerosis.High-throughput sequencing technology has helped to reveal that the bidirectional communication between the central nervous system and the enteric nervous system is facilitated by the microbiota’s diverse microorganisms,and for both neuroimmune and neuroendocrine systems.Here,we summarize the bioinformatics analysis and wet-biology validation for the gut metagenomics in neurodegenerative diseases,with an emphasis on multi-omics studies and the gut virome.The pathogen-associated signaling biomarkers for identifying brain disorders and potential therapeutic targets are also elucidated.Finally,we discuss the role of diet,prebiotics,probiotics,postbiotics and exercise interventions in remodeling the microbiome and reducing the symptoms of neurodegenerative diseases.展开更多
Cu catalysts,known for their unparalleled catalytic capabilities due to their unique electronic structure,have faced inherent challenges in maintaining long-term effectiveness under harsh hydrogenation conditions.Here...Cu catalysts,known for their unparalleled catalytic capabilities due to their unique electronic structure,have faced inherent challenges in maintaining long-term effectiveness under harsh hydrogenation conditions.Here,we demonstrate a molybdenum-mediated redispersion behavior of Cu under hightemperature oxidation conditions.The oxidized Cu nanoparticles with rich metal-support interfaces tend to dissolve into the MoO_(3)support upon heating to 600℃,which facilitates the subsequent regeneration in a reducing atmosphere.A similar redispersion phenomenon is observed for Cu nanoparticles supported on Zn O-modified MoO_(3).The modification of ZnO significantly improves the performance of the Cu catalyst for CO_(2)hydrogenation to methanol,with the high activity being well maintained after four repeated oxidation-reduction cycles.In situ spectroscopic and theoretical analyses suggest that the interaction involved in the formation of the copper molybdate-like compound is the driving force for the redispersion of Cu.This method is applicable to various Mo-based oxide supports,offering a practical strategy for the regeneration of sintered Cu particles in hydrogenation applications.展开更多
Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)p...Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)products from the same brand.Based on high-throughput sequencing research results,11 phyla and 54 genera were identified as dominant microbiota.Pseudomonas,Streptococcus,and Acinetobacter as core functional microbiota significantly influenced the UHT milk quality properties.Moreover,principal component analysis(PCA)and multivariate analyses were used to examine the quality characteristics,including 11 physicochemical parameters,10 fatty acids,and 2 enzyme activities,in normal and quality deteriorated UHT milk.We found that the abundance of Pseudomonas increased in quality deteriorated milk(WY)and showed a significant positive correlation with heat-resistant protease content.Acinetobacter in quality deteriorated milk(QY)also considerably contributed to the content of heat-resistant lipase,which resulted in spoilage deterioration of UHT milk.展开更多
Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats w...Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model group.Stomach,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter solstice.The levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent assay.Results: Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT secretion.In the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in winter.In the model group,MT levels in the colon were highest in the summer.The seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after pinealectomy.Conclusions: Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different seasons.The biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and MR.The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.展开更多
Communication could be an essential part of couples in their daily life.Based on Monitor and Acceptance Theory(MAT),the present study explored the mediating role of communication in the relationship between mindfulnes...Communication could be an essential part of couples in their daily life.Based on Monitor and Acceptance Theory(MAT),the present study explored the mediating role of communication in the relationship between mindfulness and relationship quality among college-student couples.The research examined the dynamic relationship of monitoring and acceptance to relationship satisfaction in the Actor-Partner Interdependence Model(APIM),and the mediating effect of positive or negative communications in these relationships.A total of 96 pairs of couples in the universities in Nanjing,China participated in the research.Momentary measurements were used to measure the momentary levels of their monitor,acceptance,positive/negative communication,and relationship satisfaction.A Hierarchical Linear Model(HLM)was used to deal with the APIM.Results showed that the women’s monitor facet of state mindfulness negatively predicted men’s relationship satisfaction through women’s negative communication,and the women’s acceptance facet of state mindfulness positively predicted women’s relationship satisfaction through women’s positive and negative communication at the within-person level.The study highlights the importance of cooperation in monitoring and acceptance for couples to own and hold high levels of relationship satisfaction.展开更多
This paper studies the distributed synchronization control problem of a class of stochastic dynamical systems with time-varying delays and random noise via randomly occurring control. The activation of the distributed...This paper studies the distributed synchronization control problem of a class of stochastic dynamical systems with time-varying delays and random noise via randomly occurring control. The activation of the distributed adaptive controller and the update of the control gain designed in this paper all happen randomly. Based on the Lyapunov stability theory, LaSalle invariance principle, combined with the use of the properties of the matrix Kronecker product, stochastic differential equation theory and other related tools, by constructing the appropriate Lyapunov functional, the criterion for the distributed synchronization of this type of stochastic complex networks in mean square is obtained.展开更多
During 2015, marginal scorch symptoms were detected in the production base of indigowoad rootin Hubei, China. On the basis of morphological features and 18S rDNA sequences, the pathogen was identified as Cladosporium ...During 2015, marginal scorch symptoms were detected in the production base of indigowoad rootin Hubei, China. On the basis of morphological features and 18S rDNA sequences, the pathogen was identified as Cladosporium sp. Koch’s postulates were fulfilled by pathogenicity tests on potted indigowoad root seedlings. To our knowledge, this report is the first of marginal scorch on indigowoad root caused by Cladosporium sp. We propose the name “marginal scorch” for the new disease.展开更多
Major ozonated autohemotherapy is classically used in treating ischemic disorder of the lower limbs In the present study, we performed major ozonated autohemotherapy treatment in patients with acute cerebral infarctio...Major ozonated autohemotherapy is classically used in treating ischemic disorder of the lower limbs In the present study, we performed major ozonated autohemotherapy treatment in patients with acute cerebral infarction, and assessed outcomes according to the U.S. National Institutes of Health Stroke Score, Modified Rankin Scale, and transcranial magnetic stimulation motor-evoked potential. Compared with the control group, the clinical total effective rate and the cortical potential rise rate of the upper limbs were significantly higher, the central motor conduction time of upper limb was significantly shorter, and the upper limb motor-evoked potential amplitude was significantly increased, in the ozone group. In the ozone group, the National Institutes of Health Stroke Score was positively correlated with the central motor conduction time and the motor-evoked potential amplitude of the upper limb. Central motor conduction time and motor-evoked potential amplitude of the upper limb may be effective indicators of motor-evoked potentials to assess upper limb motor function in cerebral infarct patients. Furthermore, major ozonated autohemotherapy may promote motor function recovery of the upper limb in patients with acute cerebral infarction.展开更多
Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously p...Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously produces greenhouse gas carbon dioxide.Electrochemical water splitting is a promising approach for the H2 production,which is sustainable and pollution-free.Therefore,developing efficient and economic technologies for electrochemical water splitting has been an important goal for researchers around the world.The utilization of green energy systems to reduce overall energy consumption is more important for H2 production.Harvesting and converting energy from the environment by different green energy systems for water splitting can efficiently decrease the external power consumption.A variety of green energy systems for efficient producing H2,such as two-electrode electrolysis of water,water splitting driven by photoelectrode devices,solar cells,thermoelectric devices,triboelectric nanogenerator,pyroelectric device or electrochemical water-gas shift device,have been developed recently.In this review,some notable progress made in the different green energy cells for water splitting is discussed in detail.We hoped this review can guide people to pay more attention to the development of green energy system to generate pollution-free H2 energy,which will realize the whole process of H2 production with low cost,pollution-free and energy sustainability conversion.展开更多
The IB metal(Au,Ag and Cu)alloyed Pd single atom catalysts had been proved to be efficient in promoting the selectivity for hydrogenation of acetylene to ethylene.As a base metal in the same group as Pd,the Ni-based c...The IB metal(Au,Ag and Cu)alloyed Pd single atom catalysts had been proved to be efficient in promoting the selectivity for hydrogenation of acetylene to ethylene.As a base metal in the same group as Pd,the Ni-based catalysts are also active for hydrogenation reactions.Herein,the effects of the IB metals on the Ni/SiO2 catalyst for the selective hydrogenation of acetylene were systematically studied.Different from the Pd/SiO2 catalyst,the monometallic Ni/SiO2 catalyst is not active at low temperatures.The addition of the IB metals to the Ni/SiO2 catalysts can greatly enhance the activity.Besides,the catalytic activity of the AuNix/SiO2 and CuNix/SiO2 catalysts increase with the reduction temperature,while the AgNix/SiO2 catalysts are not sensitive to the pretreatment temperature.The origin of the effect of the different IB metals on the Ni-based catalysts for selective hydrogenation of acetylene is discussed based on the characterizations by XRD,TPR and microcalorimetric measurements.展开更多
Supported Au catalysts have been reported to exhibit high ethylene selectivity in the hydrogenation of acetylene,but the conversion is relatively low.Adding a second metal to Au has proven to be a promising approach t...Supported Au catalysts have been reported to exhibit high ethylene selectivity in the hydrogenation of acetylene,but the conversion is relatively low.Adding a second metal to Au has proven to be a promising approach to enhance its catalytic performance in acetylene hydrogenation.In this work,SiO2‐supported Au‐Ni bimetallic catalysts were synthesized and investigated in the selective hydrogenation of acetylene.The Au‐Ni bimetallic catalysts exhibited much higher catalytic performance than that of the corresponding monometallic Au or Ni catalysts.By tuning the reduction temperature and/or Ni loading,we obtained an Au‐Ni/SiO2catalyst with optimal performance.The results of transmission electron microscopy imaging revealed that the Au‐Ni bimetallic particles were highly dispersed on the SiO2support.Meanwhile,analysis of the bimetallic catalyst by energy‐dispersive X‐ray spectroscopy,high‐resolution transmission electron microscopy,and in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrated the formation of Au‐Ni alloy,which contributed to the synergistic effect between Au and Ni in the hydrogenation of acetylene.展开更多
Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is am...Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is ambiguous.Herein,silica‐supported Cu-Pd bimetallic catalysts with fixed Pd content and varied Cu loadings were synthesized using an incipient wetness co‐impregnation method.The X‐ray absorption spectroscopy results indicated that Pd formed an alloy with Cu after reduction at250°C and that the Pd atoms were completely isolated by Cu for Cu/Pd atomic ratios≥40/1.Notably,increasing the reduction temperature from250to400°C hardly affected the catalytic performances of the Cu-Pd/SiO2catalysts.This finding can be attributed to the similar chemical environments of Pd demonstrated by the X‐ray absorption spectroscopy results.展开更多
Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimize...Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimized 2%Cu-NiMgAlO catalyst, ethanol conversion and n-butanol selectivity were enhanced to 30.0% and 64.2%, respectively, in 200 h time on stream at 523 K. According to physicochemical characterizations and theoretical calculations, the key role of multiple active sites in this reaction was extensively investigated. The plate-like structure of hydrotalcite was maintained over 2%Cu-NiMgAlO catalysts, with an average Ni particle size of ca. 5.4 nm. The presence of Cu species created CuNi alloy sites and Lewis acid-base pairs, and increased hydrogen transfer and condensation reactions, resulting in elevated ethanol conversion and n-butanol selectivity. Additionally, CuNi alloy had a strong interaction with CuNiMgAl oxides, forming homogeneous boundary due to their close ionic radius and lattice matching, and afforded the long time stability in the ethanol to n-butanol reaction.展开更多
基金financially supported by the National Natural Science Foundation of China,No.32002235(to MT)the Science and Technology Foundation of Taian of Shandong Province,No.2020NS216(to XL)。
文摘A growing body of evidence suggests that the gut microbiota contributes to the development of neurodegenerative diseases via the microbiota-gut-brain axis.As a contributing factor,microbiota dysbiosis always occurs in pathological changes of neurodegenerative diseases,such as Alzheimer’s disease,Parkinson’s disease,and amyotrophic lateral sclerosis.High-throughput sequencing technology has helped to reveal that the bidirectional communication between the central nervous system and the enteric nervous system is facilitated by the microbiota’s diverse microorganisms,and for both neuroimmune and neuroendocrine systems.Here,we summarize the bioinformatics analysis and wet-biology validation for the gut metagenomics in neurodegenerative diseases,with an emphasis on multi-omics studies and the gut virome.The pathogen-associated signaling biomarkers for identifying brain disorders and potential therapeutic targets are also elucidated.Finally,we discuss the role of diet,prebiotics,probiotics,postbiotics and exercise interventions in remodeling the microbiome and reducing the symptoms of neurodegenerative diseases.
基金the National Key Research and Development Program of China[No.2021YFB4000700]the CAS Project for Young Scientists in Basic Research[YSBR-022]+1 种基金the National Natural Science Foundation of China[22008136,21925803]the Welsh Government funded Taith Research Mobility Programme[No.524339]。
文摘Cu catalysts,known for their unparalleled catalytic capabilities due to their unique electronic structure,have faced inherent challenges in maintaining long-term effectiveness under harsh hydrogenation conditions.Here,we demonstrate a molybdenum-mediated redispersion behavior of Cu under hightemperature oxidation conditions.The oxidized Cu nanoparticles with rich metal-support interfaces tend to dissolve into the MoO_(3)support upon heating to 600℃,which facilitates the subsequent regeneration in a reducing atmosphere.A similar redispersion phenomenon is observed for Cu nanoparticles supported on Zn O-modified MoO_(3).The modification of ZnO significantly improves the performance of the Cu catalyst for CO_(2)hydrogenation to methanol,with the high activity being well maintained after four repeated oxidation-reduction cycles.In situ spectroscopic and theoretical analyses suggest that the interaction involved in the formation of the copper molybdate-like compound is the driving force for the redispersion of Cu.This method is applicable to various Mo-based oxide supports,offering a practical strategy for the regeneration of sintered Cu particles in hydrogenation applications.
基金supported by the National Natural Science Foundation of China(32172279,31871831)Shenyang Science and Technology Innovation Platform Project(21-103-0-14,21-104-0-28)Shenyang City Youth Science and Technology Innovation Leading Talent Project(RC200495).
文摘Commercial sterility does not guarantee the sustained stability of ultrahigh temperature(UHT)milk over 6 months shelf life.We explore the microbiota presented in normal(SZ)and quality deteriorated UHT milk(QY and WY)products from the same brand.Based on high-throughput sequencing research results,11 phyla and 54 genera were identified as dominant microbiota.Pseudomonas,Streptococcus,and Acinetobacter as core functional microbiota significantly influenced the UHT milk quality properties.Moreover,principal component analysis(PCA)and multivariate analyses were used to examine the quality characteristics,including 11 physicochemical parameters,10 fatty acids,and 2 enzyme activities,in normal and quality deteriorated UHT milk.We found that the abundance of Pseudomonas increased in quality deteriorated milk(WY)and showed a significant positive correlation with heat-resistant protease content.Acinetobacter in quality deteriorated milk(QY)also considerably contributed to the content of heat-resistant lipase,which resulted in spoilage deterioration of UHT milk.
基金supported by the National Natural Science Foundation of China(81001482 and 81973716).
文摘Objective:To investigate whether melatonin(MT)secretion in different parts of the gastrointestinal tract(GIT)exhibits seasonal variations and its correlation with immune regulation.Methods: Sixty Sprague-Dawley rats were divided into control and model groups,and the pineal gland was removed in the model group.Stomach,jejunum,ileum,and colon tissues were obtained during the spring equinox,summer solstice,beginning of autumn,autumn equinox,and winter solstice.The levels of MT,MT receptors(MR),arylalkylamine N-acetyltransferase(AANAT),hydroxyindole-O-methyltransferase(HIOMT),interleukin-2(IL-2),and interleukin-10(IL-10)in the GIT were measured using enzyme-linked immunosorbent assay.Results: Except for the stomach,the jejunum,ileum,and the colon showed seasonal tendencies in MT secretion.In the control group,MT secretion in the jejunum and ileum was the highest in the long summer,and colonic MT secretion was the highest in winter.In the model group,MT levels in the colon were highest in the summer.The seasonal rhythms of the MR,AANAT,HIOMT,IL-2,and IL-10 in the colon were roughly similar to those of MT,and changed accordingly after pinealectomy.Conclusions: Gastrointestinal MT secretion is related to seasonal changes,and MT secretion in each intestinal segment is influenced by different seasons.The biological effects of MT in the gut are inextricably linked to the mediation of MR,and a hormone-receptor linkage exists between MT and MR.The effect of seasonal changes on the gastrointestinal immune system may be mediated through the regulation of seasonal secretion of MT.
基金supported by the National Natura Science Foundation of China(Grant Number:31800929)Fundamental Research Funds for Central Universities(Grant Number:2020NTSS42).
文摘Communication could be an essential part of couples in their daily life.Based on Monitor and Acceptance Theory(MAT),the present study explored the mediating role of communication in the relationship between mindfulness and relationship quality among college-student couples.The research examined the dynamic relationship of monitoring and acceptance to relationship satisfaction in the Actor-Partner Interdependence Model(APIM),and the mediating effect of positive or negative communications in these relationships.A total of 96 pairs of couples in the universities in Nanjing,China participated in the research.Momentary measurements were used to measure the momentary levels of their monitor,acceptance,positive/negative communication,and relationship satisfaction.A Hierarchical Linear Model(HLM)was used to deal with the APIM.Results showed that the women’s monitor facet of state mindfulness negatively predicted men’s relationship satisfaction through women’s negative communication,and the women’s acceptance facet of state mindfulness positively predicted women’s relationship satisfaction through women’s positive and negative communication at the within-person level.The study highlights the importance of cooperation in monitoring and acceptance for couples to own and hold high levels of relationship satisfaction.
文摘This paper studies the distributed synchronization control problem of a class of stochastic dynamical systems with time-varying delays and random noise via randomly occurring control. The activation of the distributed adaptive controller and the update of the control gain designed in this paper all happen randomly. Based on the Lyapunov stability theory, LaSalle invariance principle, combined with the use of the properties of the matrix Kronecker product, stochastic differential equation theory and other related tools, by constructing the appropriate Lyapunov functional, the criterion for the distributed synchronization of this type of stochastic complex networks in mean square is obtained.
文摘During 2015, marginal scorch symptoms were detected in the production base of indigowoad rootin Hubei, China. On the basis of morphological features and 18S rDNA sequences, the pathogen was identified as Cladosporium sp. Koch’s postulates were fulfilled by pathogenicity tests on potted indigowoad root seedlings. To our knowledge, this report is the first of marginal scorch on indigowoad root caused by Cladosporium sp. We propose the name “marginal scorch” for the new disease.
基金supported by the Guangdong Province Medical Science Research Fund, No. B200258
文摘Major ozonated autohemotherapy is classically used in treating ischemic disorder of the lower limbs In the present study, we performed major ozonated autohemotherapy treatment in patients with acute cerebral infarction, and assessed outcomes according to the U.S. National Institutes of Health Stroke Score, Modified Rankin Scale, and transcranial magnetic stimulation motor-evoked potential. Compared with the control group, the clinical total effective rate and the cortical potential rise rate of the upper limbs were significantly higher, the central motor conduction time of upper limb was significantly shorter, and the upper limb motor-evoked potential amplitude was significantly increased, in the ozone group. In the ozone group, the National Institutes of Health Stroke Score was positively correlated with the central motor conduction time and the motor-evoked potential amplitude of the upper limb. Central motor conduction time and motor-evoked potential amplitude of the upper limb may be effective indicators of motor-evoked potentials to assess upper limb motor function in cerebral infarct patients. Furthermore, major ozonated autohemotherapy may promote motor function recovery of the upper limb in patients with acute cerebral infarction.
基金supported by Taishan Scholars Project Special Funds(tsqn201812083)Natural Science Foundation of Shandong Province(ZR2019YQ20,2019JMRH0410)the National Natural Science Foundation of China(51972147)。
文摘Hydrogen(H2)production is a latent feasibility of renewable clean energy.The industrial H2 production is obtained from reforming of natural gas,which consumes a large amount of nonrenewable energy and simultaneously produces greenhouse gas carbon dioxide.Electrochemical water splitting is a promising approach for the H2 production,which is sustainable and pollution-free.Therefore,developing efficient and economic technologies for electrochemical water splitting has been an important goal for researchers around the world.The utilization of green energy systems to reduce overall energy consumption is more important for H2 production.Harvesting and converting energy from the environment by different green energy systems for water splitting can efficiently decrease the external power consumption.A variety of green energy systems for efficient producing H2,such as two-electrode electrolysis of water,water splitting driven by photoelectrode devices,solar cells,thermoelectric devices,triboelectric nanogenerator,pyroelectric device or electrochemical water-gas shift device,have been developed recently.In this review,some notable progress made in the different green energy cells for water splitting is discussed in detail.We hoped this review can guide people to pay more attention to the development of green energy system to generate pollution-free H2 energy,which will realize the whole process of H2 production with low cost,pollution-free and energy sustainability conversion.
文摘The IB metal(Au,Ag and Cu)alloyed Pd single atom catalysts had been proved to be efficient in promoting the selectivity for hydrogenation of acetylene to ethylene.As a base metal in the same group as Pd,the Ni-based catalysts are also active for hydrogenation reactions.Herein,the effects of the IB metals on the Ni/SiO2 catalyst for the selective hydrogenation of acetylene were systematically studied.Different from the Pd/SiO2 catalyst,the monometallic Ni/SiO2 catalyst is not active at low temperatures.The addition of the IB metals to the Ni/SiO2 catalysts can greatly enhance the activity.Besides,the catalytic activity of the AuNix/SiO2 and CuNix/SiO2 catalysts increase with the reduction temperature,while the AgNix/SiO2 catalysts are not sensitive to the pretreatment temperature.The origin of the effect of the different IB metals on the Ni-based catalysts for selective hydrogenation of acetylene is discussed based on the characterizations by XRD,TPR and microcalorimetric measurements.
基金supported by the National Natural Science Foundation of China (21303194,21476227,21522608,21573232,21690084)Youth Innovation Promotion Association of the Chinese Academy of Sciences (2014163)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020100)the National Key Projects for Fundamental Research and Development of China (2016YFA0202801)the Department of Science and Technology of Liaoning Province (2015020086-101)~~
文摘Supported Au catalysts have been reported to exhibit high ethylene selectivity in the hydrogenation of acetylene,but the conversion is relatively low.Adding a second metal to Au has proven to be a promising approach to enhance its catalytic performance in acetylene hydrogenation.In this work,SiO2‐supported Au‐Ni bimetallic catalysts were synthesized and investigated in the selective hydrogenation of acetylene.The Au‐Ni bimetallic catalysts exhibited much higher catalytic performance than that of the corresponding monometallic Au or Ni catalysts.By tuning the reduction temperature and/or Ni loading,we obtained an Au‐Ni/SiO2catalyst with optimal performance.The results of transmission electron microscopy imaging revealed that the Au‐Ni bimetallic particles were highly dispersed on the SiO2support.Meanwhile,analysis of the bimetallic catalyst by energy‐dispersive X‐ray spectroscopy,high‐resolution transmission electron microscopy,and in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrated the formation of Au‐Ni alloy,which contributed to the synergistic effect between Au and Ni in the hydrogenation of acetylene.
基金supported by the National Natural Science Foundation of China(21303194,21476227,21522608 and 21690084)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2014163)+2 种基金the National Key Projects for Fundamental Research and Development of China(2016YFA0202801)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020100)the department of science and technology of Liaoning province under contract of 2015020086-101~~
文摘Cu‐alloyed Pd single‐atom catalysts exhibit excellent catalytic performance for the semi‐hydrogenation of acetylene;however,the limit of the Cu/Pd atomic ratio for forming the alloyed Pd single‐atom catalyst is ambiguous.Herein,silica‐supported Cu-Pd bimetallic catalysts with fixed Pd content and varied Cu loadings were synthesized using an incipient wetness co‐impregnation method.The X‐ray absorption spectroscopy results indicated that Pd formed an alloy with Cu after reduction at250°C and that the Pd atoms were completely isolated by Cu for Cu/Pd atomic ratios≥40/1.Notably,increasing the reduction temperature from250to400°C hardly affected the catalytic performances of the Cu-Pd/SiO2catalysts.This finding can be attributed to the similar chemical environments of Pd demonstrated by the X‐ray absorption spectroscopy results.
基金supported by the National Science Foundation of China(21690081,21721004 and 21776268)the“Transformational Technologies for Clean Energy and Demonstration,”Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 21060200)。
文摘Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimized 2%Cu-NiMgAlO catalyst, ethanol conversion and n-butanol selectivity were enhanced to 30.0% and 64.2%, respectively, in 200 h time on stream at 523 K. According to physicochemical characterizations and theoretical calculations, the key role of multiple active sites in this reaction was extensively investigated. The plate-like structure of hydrotalcite was maintained over 2%Cu-NiMgAlO catalysts, with an average Ni particle size of ca. 5.4 nm. The presence of Cu species created CuNi alloy sites and Lewis acid-base pairs, and increased hydrogen transfer and condensation reactions, resulting in elevated ethanol conversion and n-butanol selectivity. Additionally, CuNi alloy had a strong interaction with CuNiMgAl oxides, forming homogeneous boundary due to their close ionic radius and lattice matching, and afforded the long time stability in the ethanol to n-butanol reaction.
