The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sit...The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.展开更多
Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),wh...Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),which exhibits excellent hydrothermal stability and exceptional activity for this reaction.The oxidative cleavage of 2-phenoxyacetophenone,1,a lignin model compound,over Cu-MOP-e at 90℃for 1 h affords full conversion with yields of the monomer products phenol and benzoic acid of 99%.The reusability of Cu-MOP-e was confirmed by carrying out ten cycles of reaction.The mechanism of catalyst-substrate binding was investigated by highresolution synchrotron X-ray powder diffraction,in situ X-ray absorption spectroscopy,electron paramagnetic resonance spectroscopy,and density functional theory(DFT)calculations.The combination of optimal porosity and active Cu(Ⅱ)sites provides confined binding of 2-phenoxyacetophenone,thus promoting the cleavage ofβ-O-4 linkage under relatively mild conditions.展开更多
基金University of Manchester,the National Natural Science Foundation of China and BNLMS for funding,and the EPSRC for funding of the EPSRC National EPR Facility at Manchester(EP/W014532/1 and EP/X034623/1)We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectively+8 种基金We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectivelyWe acknowledge the UK catalysis Hub Block Allocation Group(BAG)Programme Mode Application for provision of beamtime at B18 for collection of the data presented in this work and the initial discussion of the dataThe UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC grant:EP/R026939,EP/R026815,EP/R026645,EP/R027129 and EP/M013219(biocatalysis)We acknowledge the support of The University of Manchester's Dalton Cumbrian Facility(DCF),a partner in the National Nuclear User FacilityWe recognise Dr.R.Edge for the assistance during the 60Co-irradiation processesWe thank M.Kibble for help at ISIS beamlinesTEM access was supported by the Henry Royce Institute for Advanced Materials,funded through EPSRC grants EP/R00661X,EP/S019367,EP/P025021 and EP/P025498Zhaodong Zhu thanks the President's Doctoral Scholar award of University of Manchester for fundingMeng He and Lutong Shan thank the China Scholarship Council(CSC)for funding.
文摘The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.
基金supported by the Engineering and Physical Sciences Research Council(EPSRC),UK(grant nos.EP/I011870 and EP/K014706/2)the Royal Society,UK(grant no.IC170327)+2 种基金the National Natural Science Foundation of China(grant nos.22273108,21733011,and 21890761)the European Research Council(ERC)under the European Union’s Horizon 2020 Research and Innovation Program,Brussels,Belgium(grant no.742401,NANOCHEM)the Beijing Natural Science Foundation,China(grant no.2222043).
文摘Catalytic cleavage ofβ-O-4 linkages is an essential but challenging step in the depolymerization of lignin.Here,we report the templated electrosynthesis of a hydrophobic metal-organic polyhedral catalyst(Cu-MOP-e),which exhibits excellent hydrothermal stability and exceptional activity for this reaction.The oxidative cleavage of 2-phenoxyacetophenone,1,a lignin model compound,over Cu-MOP-e at 90℃for 1 h affords full conversion with yields of the monomer products phenol and benzoic acid of 99%.The reusability of Cu-MOP-e was confirmed by carrying out ten cycles of reaction.The mechanism of catalyst-substrate binding was investigated by highresolution synchrotron X-ray powder diffraction,in situ X-ray absorption spectroscopy,electron paramagnetic resonance spectroscopy,and density functional theory(DFT)calculations.The combination of optimal porosity and active Cu(Ⅱ)sites provides confined binding of 2-phenoxyacetophenone,thus promoting the cleavage ofβ-O-4 linkage under relatively mild conditions.
