The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temp...A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temperature.Pt@ZIF-8 was highly porous and well crystallized.The Pt nanoparticles were well dispersed within the ZIF-8 support.In the hydrogenation of 1,4-butynediol,Pt@ZIF-8 exhibited high activity,excellent selectivity for 1,4-butenediol of greater than 94%,and reusability.The Pt@ZIF-8 catalyst did not require further additives.The favorable catalytic performance was attributed primarily to the modification of the ZIF-8 support by the platinum nanoparticles.展开更多
The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic perf...The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic performance of Ni-Al2O3 catalyst for hydrogenation of 1,4-butynediol to produce 1,4-butenediol were investigated.The catalysts were characterized by PSD,EDX,XRD,H2-TPR,BET,TEM,and NH3-TPD methods.Results showed that the MCt2.5 catalyst treated at a ball milling time of 2.5 h could form a smallest particle size of 191.0 nm.The evaluation experiments revealed that the activity of the prepared catalyst increased at first and then reached a constant value with the extension of ballmilling time.The BYD conversion,BED selectivity and yield on the MCt2.5 catalyst reached 35.63%,33.48%and 32.46%,respectively,which were higher than those obtained by other samples.The excellent performance of MCt2.5 sample is mainly related to the following three reasons from characterization results.Firstly,it has a smallest particle size of 191.0 nm;and then,the surface acidity(in terms of strong acids)of the catalyst was weaker than other catalysts;and eventually,the loading amount(23.84%)of the active component Ni exceeded the theoretical value(20%).展开更多
Transition metal-catalyzed C—C coupling reactions are a core strategy for the construction of carbon-carbon bonds in organic synthesis.Their development has not only promoted the synthesis of drugs,materials,and natu...Transition metal-catalyzed C—C coupling reactions are a core strategy for the construction of carbon-carbon bonds in organic synthesis.Their development has not only promoted the synthesis of drugs,materials,and natural products,but also promoted the development of new synthetic methods,and has also made breakthroughs in mechanism innovation and catalyst design.On this basis,a copper-catalyzed radical reaction between ketones is reported,enabling the synthesis of 2-carbonyl-1,4-diones.The method exhibits excellent applicability to multiple structural types of ketones,including aliphatic ketones with diverse substituents,aromatic ketones,and various simple ketones not limited to acetone,with wide applications,easy implementation,low catalyst toxicity,and low cost,cost-effective,and the product is easy to separate and purify.展开更多
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
基金supported by the National Natural Science Foundation of China(21573031 and 21428301)the Fundamental Research Funds for the Central Universities(DUT15ZD106 and DUT15RC(4)09)~~
文摘A catalyst consisting of platinum nanoparticles on a ZIF-8 support（Pt@ZIF-8） was synthesized in a straightforward one-step procedure,by adding a nanostructured platinum sol during the formation of ZIF-8 at room temperature.Pt@ZIF-8 was highly porous and well crystallized.The Pt nanoparticles were well dispersed within the ZIF-8 support.In the hydrogenation of 1,4-butynediol,Pt@ZIF-8 exhibited high activity,excellent selectivity for 1,4-butenediol of greater than 94%,and reusability.The Pt@ZIF-8 catalyst did not require further additives.The favorable catalytic performance was attributed primarily to the modification of the ZIF-8 support by the platinum nanoparticles.
基金This work has been supported by the Xinjiang Uygur Autonomous Region Key R&D Program(2017B02012)the Xinjiang University Natural Science Foundation Project(BS160221).
文摘The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic performance of Ni-Al2O3 catalyst for hydrogenation of 1,4-butynediol to produce 1,4-butenediol were investigated.The catalysts were characterized by PSD,EDX,XRD,H2-TPR,BET,TEM,and NH3-TPD methods.Results showed that the MCt2.5 catalyst treated at a ball milling time of 2.5 h could form a smallest particle size of 191.0 nm.The evaluation experiments revealed that the activity of the prepared catalyst increased at first and then reached a constant value with the extension of ballmilling time.The BYD conversion,BED selectivity and yield on the MCt2.5 catalyst reached 35.63%,33.48%and 32.46%,respectively,which were higher than those obtained by other samples.The excellent performance of MCt2.5 sample is mainly related to the following three reasons from characterization results.Firstly,it has a smallest particle size of 191.0 nm;and then,the surface acidity(in terms of strong acids)of the catalyst was weaker than other catalysts;and eventually,the loading amount(23.84%)of the active component Ni exceeded the theoretical value(20%).
基金Project supported by the Basic Research Support Program for Outstanding Young Teachers in Provincial Undergraduate Colleges and Universities in Heilongjiang Province(No.YQJH2024096)the Heilongjiang Province Natural Joint Guidance Cultivation Project(No.PL2024H198)。
文摘Transition metal-catalyzed C—C coupling reactions are a core strategy for the construction of carbon-carbon bonds in organic synthesis.Their development has not only promoted the synthesis of drugs,materials,and natural products,but also promoted the development of new synthetic methods,and has also made breakthroughs in mechanism innovation and catalyst design.On this basis,a copper-catalyzed radical reaction between ketones is reported,enabling the synthesis of 2-carbonyl-1,4-diones.The method exhibits excellent applicability to multiple structural types of ketones,including aliphatic ketones with diverse substituents,aromatic ketones,and various simple ketones not limited to acetone,with wide applications,easy implementation,low catalyst toxicity,and low cost,cost-effective,and the product is easy to separate and purify.
