Methanol,a crucial C1 intermediate,bridges traditional fossil-based chemical processes with emerging sustainable catalytic technologies by serving as both a versatile hydrogenation product from CO/CO_(2)and an active ...Methanol,a crucial C1 intermediate,bridges traditional fossil-based chemical processes with emerging sustainable catalytic technologies by serving as both a versatile hydrogenation product from CO/CO_(2)and an active intermediate for hydrocarbon synthesis.Despite significant progress in methanol-to-hydrocarbon(MTH)conversion,a comprehensive understanding of reaction mechanisms remains essential to enhance catalyst design and industrial applicability.This review critically synthesizes recent advances in mechanistic insights related to methanol conversion and methanol-mediated catalytic processes.Firstly,we systematically outline key reaction pathways involved in initial carbon–carbon(C–C)bond formation through direct and indirect mechanisms,emphasizing significant breakthroughs from spectroscopic analyses and theoretical calculations.Subsequently,we highlight the autocatalytic characteristics and dual-cycle mechanisms underlying MTH processes,critically evaluating the roles of zeolite structures,pore sizes,topology,and acidity in governing product selectivity and catalyst stability.Additionally,we discuss cutting-edge developments in tandem catalytic systems employing methanol as a pivotal intermediate for CO_(x)hydrogenation,emphasizing the transferable mechanistic principles and catalytic insights.Finally,we identify future research directions,including elucidating precise hydrocarbon pool(HCP)intermediates,optimizing zeolite structures through computational-guided design,and developing robust catalytic systems leveraging advanced characterization methods and artificial intelligence.By integrating multidisciplinary approaches from catalytic science,materials engineering,and reaction engineering,this review provides actionable guidance towards rational design and optimization of advanced catalytic systems for efficient methanol conversion processes.展开更多
Universal time(UT)1 is an alternative description of the Earth’s rotation angle and is one of the spatial parameters representing the Earth’s orientation that reflects subtle changes in its rotational speed.While ve...Universal time(UT)1 is an alternative description of the Earth’s rotation angle and is one of the spatial parameters representing the Earth’s orientation that reflects subtle changes in its rotational speed.While very long baseline interferometry(VLBI)has recently achieved high-precision measurements of UT1,its prohibitively high equipment costs and complex data processes make it difficult to meet the requirements of users in fields with stringent real-time data requirements,such as astronomical measurement and celestial navigation.Currently,the digital zenith telescope is one of the most accurate ground-based optical astronomical measurement instruments available.This study briefly introduces the digital zenith telescope measurement system and the basic principles of UT1 measurement and data processing.On the basis of more than 400 UT1 measurement experiments conducted at Luonan,Lijiang,and Delingha,the accuracy of UT1 measurements based on the digital zenith telescope is analyzed.The experimental results show that the internal consistency accuracy within 20 min can reach 10 ms and that the internal consistency accuracy of single-day observations can reach 0.05″.Compared with IERS 14C04,the mean absolute error of the UT1 measurements is approximately 3 ms.This indicates that optical astronomical observations based on the digital zenith telescope can be used as an effective regional autonomous monitoring method to supplement VLBI by providing highfrequency UT1,functioning in particular as an emergency backup when satellite navigation fails.展开更多
Coke formation is the primary cause of zeolite deactivation in industrial catalysis,yet the structural identity,spatial location and molecular routes of polycyclic aromatic hydrocarbons(PAHs)within confined zeolite po...Coke formation is the primary cause of zeolite deactivation in industrial catalysis,yet the structural identity,spatial location and molecular routes of polycyclic aromatic hydrocarbons(PAHs)within confined zeolite pores remain elusive.Here,by coupling matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry with multi-dimensional chemical imaging,we unveil a channel-passing growth mechanism for PAHs in ZSM-5 zeolites during methanol conversion through identifying the molecular fingerprints of larger PAHs,pinpointing and visualizing their 3D location and spatiotemporal evolution trajectory with atomic resolution and at both channel and single-crystal scales.Confined aromatic entities cross-link with each other,culminating in multicore PAH chains as the both thermodynamically favorable and kinetically trapped host-vip entanglement wrought and templated by the defined molecular-scale constrained microenvironments of zeolite.The mechanistic concept proves general across both channel-and cage-structured zeolite materials.Our multiscale deactivating model based on the full-picture coke structure-location correlations—spanning atom,molecule,channel/cage and single crystal scales—would shed new light on the intertwined chemical and physical processes in catalyst deactivation.This work not only resolves long-standing puzzles in coke formation but also provides design principles for coke-resistant zeolites.The methods and insights would rekindle interest in confinement effects and host-vip chemistry across broader chemistry fields beyond catalysis and carbon materials.展开更多
基金the Inner Mongolia Natural Science Foundation(2023ZD05,2025JQ028,2025MS02001)the National Natural Science Foundation of China(22278238,22238004)+3 种基金the National Key Research and Development Program of China(2024YFE0211400)the Major Science and Technology Program of Inner Mongolia Autonomous Region(20212120326)the“Elite Talents Revitalize Inner Mongolia”Initiative–Tier-1 Talent Team(202410)the Ordos Science and Technology Breakthrough(JBGS2024003),and Ordos Laboratory for their financial support.
文摘Methanol,a crucial C1 intermediate,bridges traditional fossil-based chemical processes with emerging sustainable catalytic technologies by serving as both a versatile hydrogenation product from CO/CO_(2)and an active intermediate for hydrocarbon synthesis.Despite significant progress in methanol-to-hydrocarbon(MTH)conversion,a comprehensive understanding of reaction mechanisms remains essential to enhance catalyst design and industrial applicability.This review critically synthesizes recent advances in mechanistic insights related to methanol conversion and methanol-mediated catalytic processes.Firstly,we systematically outline key reaction pathways involved in initial carbon–carbon(C–C)bond formation through direct and indirect mechanisms,emphasizing significant breakthroughs from spectroscopic analyses and theoretical calculations.Subsequently,we highlight the autocatalytic characteristics and dual-cycle mechanisms underlying MTH processes,critically evaluating the roles of zeolite structures,pore sizes,topology,and acidity in governing product selectivity and catalyst stability.Additionally,we discuss cutting-edge developments in tandem catalytic systems employing methanol as a pivotal intermediate for CO_(x)hydrogenation,emphasizing the transferable mechanistic principles and catalytic insights.Finally,we identify future research directions,including elucidating precise hydrocarbon pool(HCP)intermediates,optimizing zeolite structures through computational-guided design,and developing robust catalytic systems leveraging advanced characterization methods and artificial intelligence.By integrating multidisciplinary approaches from catalytic science,materials engineering,and reaction engineering,this review provides actionable guidance towards rational design and optimization of advanced catalytic systems for efficient methanol conversion processes.
基金supported by the National Natural Science Foundation of China(41704006,42204041,and 42374011)the Natural Science Foundation Outstanding Youth Fund Program of Henan Province(242300421150)the Key Laboratory of Smart Earth(SYS-ZX06-2024-01).
文摘Universal time(UT)1 is an alternative description of the Earth’s rotation angle and is one of the spatial parameters representing the Earth’s orientation that reflects subtle changes in its rotational speed.While very long baseline interferometry(VLBI)has recently achieved high-precision measurements of UT1,its prohibitively high equipment costs and complex data processes make it difficult to meet the requirements of users in fields with stringent real-time data requirements,such as astronomical measurement and celestial navigation.Currently,the digital zenith telescope is one of the most accurate ground-based optical astronomical measurement instruments available.This study briefly introduces the digital zenith telescope measurement system and the basic principles of UT1 measurement and data processing.On the basis of more than 400 UT1 measurement experiments conducted at Luonan,Lijiang,and Delingha,the accuracy of UT1 measurements based on the digital zenith telescope is analyzed.The experimental results show that the internal consistency accuracy within 20 min can reach 10 ms and that the internal consistency accuracy of single-day observations can reach 0.05″.Compared with IERS 14C04,the mean absolute error of the UT1 measurements is approximately 3 ms.This indicates that optical astronomical observations based on the digital zenith telescope can be used as an effective regional autonomous monitoring method to supplement VLBI by providing highfrequency UT1,functioning in particular as an emergency backup when satellite navigation fails.
文摘Coke formation is the primary cause of zeolite deactivation in industrial catalysis,yet the structural identity,spatial location and molecular routes of polycyclic aromatic hydrocarbons(PAHs)within confined zeolite pores remain elusive.Here,by coupling matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry with multi-dimensional chemical imaging,we unveil a channel-passing growth mechanism for PAHs in ZSM-5 zeolites during methanol conversion through identifying the molecular fingerprints of larger PAHs,pinpointing and visualizing their 3D location and spatiotemporal evolution trajectory with atomic resolution and at both channel and single-crystal scales.Confined aromatic entities cross-link with each other,culminating in multicore PAH chains as the both thermodynamically favorable and kinetically trapped host-vip entanglement wrought and templated by the defined molecular-scale constrained microenvironments of zeolite.The mechanistic concept proves general across both channel-and cage-structured zeolite materials.Our multiscale deactivating model based on the full-picture coke structure-location correlations—spanning atom,molecule,channel/cage and single crystal scales—would shed new light on the intertwined chemical and physical processes in catalyst deactivation.This work not only resolves long-standing puzzles in coke formation but also provides design principles for coke-resistant zeolites.The methods and insights would rekindle interest in confinement effects and host-vip chemistry across broader chemistry fields beyond catalysis and carbon materials.
