Methanol-to-olefins(MTO)process is one of the most critical pathways to produce low carbon olefins.Typically,the reaction is driven by thermal catalysis,which inevitably needs to consume large amounts of fossil fuel.D...Methanol-to-olefins(MTO)process is one of the most critical pathways to produce low carbon olefins.Typically,the reaction is driven by thermal catalysis,which inevitably needs to consume large amounts of fossil fuel.Developing a new technique to substitute for the fuel burning is urgent for MTO process to improve the industry prospects and sustainability.Herein,we report a novel W_(18)O_(49)/Au/SAPO-34(W/Au/S),a multifunctional photothermal catalyst for the MTO reaction.A high methanol conversion was achieved under xenonum(Xe)lamp irradiation,yielding methyl ether(ME)and ethylene as the main products.The optimized W/Au/S catalysts showed ethylene yield as high as 250μmol in 60 min,which was 2.5 times higher than that of Au/SAPO-34.The physiochemical characterization revealed that the SAPO-34 molecular sieves were surrounded by Au and W_(18)O_(49)nanoparticles,which exhibited a strong localized surface plasmon resonance excitation around 540 nm and light absorption beyond 500 nm.The multifunctional catalysts showed a strong photothermal effect,arising from the broadened light absorption of Au and W_(18)O_(49)nanoparticles,leading to a temperature as high as 250℃on the surface of the catalysts.Mechanism study showed that the superior ethylene selectivity of W/Au/S catalysts was attributed to the moderating acidic sites of W_(18)O_(49)for methanol dehydration to ethylene.This research may provide new insight for designing heterostructures to improve photo-to-chemical conversion performance and is expected to accelerate progress toward the excellent multifunctional photothermal catalysts with broad light absorption for methanol activation and C-C bond formation.展开更多
Boron removal from metallurgical-grade silicon(MG-Si) using CaO–SiO2 slag was studied by employing a medium-frequency electromagnetic induction furnace.The relationship between the optical basicity(K)of the CaO–SiO2...Boron removal from metallurgical-grade silicon(MG-Si) using CaO–SiO2 slag was studied by employing a medium-frequency electromagnetic induction furnace.The relationship between the optical basicity(K)of the CaO–SiO2 slag and the distribution coefficient of boron(LB) was investigated.Consequently, the local minimum and maximum LBvalues of 0.72 and 1.58 are obtained when K = 0.56 and K = 0.71, respectively.The boron content in MG-Si decreases gradually with refinement time increasing, down to a minimum value of4.73 9 10-6.The controlling step in the removal of boron from MG-Si is not the chemical reaction at the interface of the slag and silicon.Instead, the controlling step is a diffusion mass transfer, in which boron impurities diffuse from molten silicon to the interface of the slag and silicon,or B2O3 formed by the chemical reaction diffuses from the slag–silicon interface to molten slag.展开更多
基金the National Key R&D Program of China(Nos.2018YFC1901805,2018YFC1901801)the Reserve Talents of Young and Middle-aged Academic and Technical Leaders in Yunnan Province,China(No.2018HB009)+1 种基金the Program for Innovative Research Team in University of the Ministry of Education of China(No.IRT-17R48)the Major Project of Science and Technology Department of Yunnan Province,China(No.2019ZE007).
基金the financial supports from the National Natural Science Foundation of China(No.U1902219)the Yunnan Young and Middle-aged Academic and Technical Leader Reserve Talent Project,China(No.2018HB009)+1 种基金the Yunnan Outstanding Youth Science Foundation,China(No.202101AV070007)the Major Science and Technology Projects in Yunnan Province,China(Nos.2019ZE007,202002AB080002)。
基金financially supported by the High-level Innovative Talent Cultivation Project of Guizhou Province(No.GZSQCC2019003)the Natural Science Research Project of Guizhou Provincial Department of Education(No.QJHKY Zi[2021]257)the Academic New Seedling Cultivation and Innovation Exploration Project of Guizhou Institute of Technology(No.GZLGXM-08)。
文摘Methanol-to-olefins(MTO)process is one of the most critical pathways to produce low carbon olefins.Typically,the reaction is driven by thermal catalysis,which inevitably needs to consume large amounts of fossil fuel.Developing a new technique to substitute for the fuel burning is urgent for MTO process to improve the industry prospects and sustainability.Herein,we report a novel W_(18)O_(49)/Au/SAPO-34(W/Au/S),a multifunctional photothermal catalyst for the MTO reaction.A high methanol conversion was achieved under xenonum(Xe)lamp irradiation,yielding methyl ether(ME)and ethylene as the main products.The optimized W/Au/S catalysts showed ethylene yield as high as 250μmol in 60 min,which was 2.5 times higher than that of Au/SAPO-34.The physiochemical characterization revealed that the SAPO-34 molecular sieves were surrounded by Au and W_(18)O_(49)nanoparticles,which exhibited a strong localized surface plasmon resonance excitation around 540 nm and light absorption beyond 500 nm.The multifunctional catalysts showed a strong photothermal effect,arising from the broadened light absorption of Au and W_(18)O_(49)nanoparticles,leading to a temperature as high as 250℃on the surface of the catalysts.Mechanism study showed that the superior ethylene selectivity of W/Au/S catalysts was attributed to the moderating acidic sites of W_(18)O_(49)for methanol dehydration to ethylene.This research may provide new insight for designing heterostructures to improve photo-to-chemical conversion performance and is expected to accelerate progress toward the excellent multifunctional photothermal catalysts with broad light absorption for methanol activation and C-C bond formation.
基金financially supported by the National Natural Science Foundation of China (Nos. 51461027 and 51104080)
文摘Boron removal from metallurgical-grade silicon(MG-Si) using CaO–SiO2 slag was studied by employing a medium-frequency electromagnetic induction furnace.The relationship between the optical basicity(K)of the CaO–SiO2 slag and the distribution coefficient of boron(LB) was investigated.Consequently, the local minimum and maximum LBvalues of 0.72 and 1.58 are obtained when K = 0.56 and K = 0.71, respectively.The boron content in MG-Si decreases gradually with refinement time increasing, down to a minimum value of4.73 9 10-6.The controlling step in the removal of boron from MG-Si is not the chemical reaction at the interface of the slag and silicon.Instead, the controlling step is a diffusion mass transfer, in which boron impurities diffuse from molten silicon to the interface of the slag and silicon,or B2O3 formed by the chemical reaction diffuses from the slag–silicon interface to molten slag.
