The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a...The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a catalyst, Cu2+ loading SAPO-17, synthesized using cyclohexylamine(CHA), which is commercially available and inexpensive and is utilized in NH3-SCR reduction for the first time. After systematic investigations on the optimization of Si and Cu2+ contents, it was concluded that Cu-SAPO-17-8.0%-0.22 displays favorable catalytic performance, even after being heated at 353 K for 24 h and at 973 K for 16 h. Moreover, the locations of CHAs, host–guest interaction and the Bronsted acid sites were explored by Rietveld refinement against powder X-ray diffraction data of as-made SAPO-17-8.0%. The refinement results showed that two CHAs exist within one eri cage and that the protonated CHA forms a hydrogen bond with O4, which indicates that the proton bonding with O4 will form the Bronsted acid site after the calcination.展开更多
CO2 capture,especially under low-pressure range,is of significance to maintain long-duration human operation in confined spaces and decrease the CO2 corrosion and freezing effect for the liquefaction of natural gas.He...CO2 capture,especially under low-pressure range,is of significance to maintain long-duration human operation in confined spaces and decrease the CO2 corrosion and freezing effect for the liquefaction of natural gas.Herein,we for the first time report a novel anion-functionalized ZU-16-Co(TIFSIX-3-Co,TIFSIX=hexafluorotitanate(TiF62−),3=pyrazine),which exhibits one-dimensional pore channels decorated by abundant F atoms,for efficient CO2 capture at a concentration around 400–10,000 ppm.Among its isostructural MFSIX-3(M=Si,Ti,Ge)family materials,ZU-16-Co with fine-tuned pore size of 3.62Åexhibits the highest CO2 uptake at 0.01 bar(10,000 ppm)and 1 bar(2.63 and 2.87 mmol g−,respectively).The high CO2 capture ability of ZU-16-Co originates from the fine-tuned pore dimensions with strong F⋯C=O host-guest interactions and relatively large pore volumes coming from its longer coordinated Ti-F-Co distance(3.9Å)in c direction.The excellent carbon trapping performance was further verified by dynamic breakthrough tests for CO2/N2(1/99 and 15/85)and CO2/CH4(50/50)mixtures.The adsorption and separation performances,resulting from the fine-tuned pore system with periodic arrays of exposed functionalities,demonstrate that ultramicroporous ZU-16-Co can be a promising adsorbent for low-concentration carbon capture.展开更多
文摘The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a catalyst, Cu2+ loading SAPO-17, synthesized using cyclohexylamine(CHA), which is commercially available and inexpensive and is utilized in NH3-SCR reduction for the first time. After systematic investigations on the optimization of Si and Cu2+ contents, it was concluded that Cu-SAPO-17-8.0%-0.22 displays favorable catalytic performance, even after being heated at 353 K for 24 h and at 973 K for 16 h. Moreover, the locations of CHAs, host–guest interaction and the Bronsted acid sites were explored by Rietveld refinement against powder X-ray diffraction data of as-made SAPO-17-8.0%. The refinement results showed that two CHAs exist within one eri cage and that the protonated CHA forms a hydrogen bond with O4, which indicates that the proton bonding with O4 will form the Bronsted acid site after the calcination.
基金the National Natural Science Foundation of China(21938011,U1862110,21890764 and21725603)the National Program for Support of Top-notch Young Professionals(H.X.)。
文摘CO2 capture,especially under low-pressure range,is of significance to maintain long-duration human operation in confined spaces and decrease the CO2 corrosion and freezing effect for the liquefaction of natural gas.Herein,we for the first time report a novel anion-functionalized ZU-16-Co(TIFSIX-3-Co,TIFSIX=hexafluorotitanate(TiF62−),3=pyrazine),which exhibits one-dimensional pore channels decorated by abundant F atoms,for efficient CO2 capture at a concentration around 400–10,000 ppm.Among its isostructural MFSIX-3(M=Si,Ti,Ge)family materials,ZU-16-Co with fine-tuned pore size of 3.62Åexhibits the highest CO2 uptake at 0.01 bar(10,000 ppm)and 1 bar(2.63 and 2.87 mmol g−,respectively).The high CO2 capture ability of ZU-16-Co originates from the fine-tuned pore dimensions with strong F⋯C=O host-guest interactions and relatively large pore volumes coming from its longer coordinated Ti-F-Co distance(3.9Å)in c direction.The excellent carbon trapping performance was further verified by dynamic breakthrough tests for CO2/N2(1/99 and 15/85)and CO2/CH4(50/50)mixtures.The adsorption and separation performances,resulting from the fine-tuned pore system with periodic arrays of exposed functionalities,demonstrate that ultramicroporous ZU-16-Co can be a promising adsorbent for low-concentration carbon capture.
