An open-framework zinc-cobalt phosphate CoZnPO4-V with 16-ring extra-large-pore channels has been obtained in the presence of chain-type polyamines as the structure directing agent (SDA). Its large single crystal suit...An open-framework zinc-cobalt phosphate CoZnPO4-V with 16-ring extra-large-pore channels has been obtained in the presence of chain-type polyamines as the structure directing agent (SDA). Its large single crystal suited for structure refinement has been prepared with the assistance of small organic amines. Single-crystal X-ray diffraction analysis has shown that CoZnPO4-V is a novel metal phosphate. It crystallizes in monoclinic space group P21/c (No. 14), with a = 31.936(3) , b = 8.3775(7) , c = 15.7874(13) , α = γ = 90°, β = 97.0530(10)°, V = 4191.8(6) 3, and Z = 4 with R1 = 0.0455,wR2 = 0.0869. Its three-dimensional framework can be considered as stacking from two-dimensional nets and one-dimensional units as linkers. Between the stacking nets and linkers are located extra-large channels with 16-ring apertures.展开更多
Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to ...Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite synthesis.Herein,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–6.8.The prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 ratio.The XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.展开更多
In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,a...In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,at variance with any other aluminosilicate zeolites,can serve as heterogeneous seeds for the growth of IWR zeolites and play a cooperative structure-directing role.The crystallization process was investigated using multiple techniques to characterize a series of solid products obtained with various crystallization times.The experiments clearly showed the dissolution of the*BEA zeolite and of an intermediate CDO-type structure.A plausible mechanism for the novel cooperative synthesis has been proposed.The crystallization of the IWR zeolite involves several steps,among which the crucial one is believed to be the reassembly of the building units produced from the decomposition of*BEA zeolite seeds,induced by choline molecules.Having similar structure and common building units(four-,five-,and six-membered rings)with the IWR zeolite,the*BEA zeolite is capable of promoting the reassembly of the building units and can thus play a cooperative structure-directing role.By highlighting the cooperative structure-directing effect of organic molecules and heterogeneous seeds,this study opens up new perspectives for the synthesis of target zeolites that are difficult to prepare by traditional methods.This new synthetic route is also expected to shed light on the discovery of novel zeolites.展开更多
Zeolites have been widely applied in many chemical processes owing to their featured microporous framework structures.Organic structure-directing agents(OSDAs) play an important role during of the formation of zeolite...Zeolites have been widely applied in many chemical processes owing to their featured microporous framework structures.Organic structure-directing agents(OSDAs) play an important role during of the formation of zeolite frameworks via non-bonding host-guest interactions.Understanding these interactions is crucial to the design of OSDAs and the synthesis of target zeolites.Here,we report a molecular simulation study in the host-guest interactions between zeolite framework STW and 21 alkylated imidazolium and pyrazolium cations that have been used as the OSDAs for the synthesis of STW-type zeolites.We find that OSDAs that have successfully directed the formation of STW exhibit stronger host-guest interactions than unsuccessful ones.Furthermore,we find all successful OSDAs possess relatively more negative atomic charges on nitrogen atoms and smaller dipole moments.According to this finding,we have designed seven new alkylated imidazolium and pyrazolium cations that may be suitable for zeolite STW,and verified their structure-directing capability by molecular simulation calculations.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 20873069)973 Project (Grant No. 2009CB623502)
文摘An open-framework zinc-cobalt phosphate CoZnPO4-V with 16-ring extra-large-pore channels has been obtained in the presence of chain-type polyamines as the structure directing agent (SDA). Its large single crystal suited for structure refinement has been prepared with the assistance of small organic amines. Single-crystal X-ray diffraction analysis has shown that CoZnPO4-V is a novel metal phosphate. It crystallizes in monoclinic space group P21/c (No. 14), with a = 31.936(3) , b = 8.3775(7) , c = 15.7874(13) , α = γ = 90°, β = 97.0530(10)°, V = 4191.8(6) 3, and Z = 4 with R1 = 0.0455,wR2 = 0.0869. Its three-dimensional framework can be considered as stacking from two-dimensional nets and one-dimensional units as linkers. Between the stacking nets and linkers are located extra-large channels with 16-ring apertures.
基金supported by the National Natural Science Foundation of China(Grant No.21802136)~~
文摘Zeolite synthesis in contemporary chemical industries is predominantly conducted using organic structure‐directing agents(OSDAs),which are chronically hazardous to humans and the environment.It is a growing trend to develop an eco‐friendly and nuisanceless OSDA for zeolite synthesis.Herein,choline is employed as a non‐toxic and green OSDA to synthesize high silica Y zeolite with SiO2/Al2O3 ratios of 6.5–6.8.The prepared Y zeolite samples exhibited outstanding(hydro)thermal stability at ultrahigh temperature owing to the higher SiO2/Al2O3 ratio.The XRF,SEM,29Si‐NMR and 13Na+results suggested that choline plays a structure‐directing role in the synthesis of Y zeolite,while the feed molar fraction of Na+is a crucial determinant for the framework SiO2/Al2O3 ratio and the crystal morphology.
基金supported by the National Key R&D Program of China(2017YFB0702800)National Natural Science Foundation of China(21802168,21503280,21603277)China Petrochemical Corporation(Sinopec Group)~~
文摘In this contribution,we report the cooperative structure-directing effect of choline hydroxide and aluminosilicate*BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolites for the first time.*BEA zeolites,at variance with any other aluminosilicate zeolites,can serve as heterogeneous seeds for the growth of IWR zeolites and play a cooperative structure-directing role.The crystallization process was investigated using multiple techniques to characterize a series of solid products obtained with various crystallization times.The experiments clearly showed the dissolution of the*BEA zeolite and of an intermediate CDO-type structure.A plausible mechanism for the novel cooperative synthesis has been proposed.The crystallization of the IWR zeolite involves several steps,among which the crucial one is believed to be the reassembly of the building units produced from the decomposition of*BEA zeolite seeds,induced by choline molecules.Having similar structure and common building units(four-,five-,and six-membered rings)with the IWR zeolite,the*BEA zeolite is capable of promoting the reassembly of the building units and can thus play a cooperative structure-directing role.By highlighting the cooperative structure-directing effect of organic molecules and heterogeneous seeds,this study opens up new perspectives for the synthesis of target zeolites that are difficult to prepare by traditional methods.This new synthetic route is also expected to shed light on the discovery of novel zeolites.
基金the National Natural Science Foundation of China(Nos.21622102,21621001 and 21920102005)the National Key Research and Development Program of China(No.2016YFB0701100)+1 种基金the National 111 Project(No.B17020)Program for JLUSTIRT and High Performance Computing Center of Jilin University。
文摘Zeolites have been widely applied in many chemical processes owing to their featured microporous framework structures.Organic structure-directing agents(OSDAs) play an important role during of the formation of zeolite frameworks via non-bonding host-guest interactions.Understanding these interactions is crucial to the design of OSDAs and the synthesis of target zeolites.Here,we report a molecular simulation study in the host-guest interactions between zeolite framework STW and 21 alkylated imidazolium and pyrazolium cations that have been used as the OSDAs for the synthesis of STW-type zeolites.We find that OSDAs that have successfully directed the formation of STW exhibit stronger host-guest interactions than unsuccessful ones.Furthermore,we find all successful OSDAs possess relatively more negative atomic charges on nitrogen atoms and smaller dipole moments.According to this finding,we have designed seven new alkylated imidazolium and pyrazolium cations that may be suitable for zeolite STW,and verified their structure-directing capability by molecular simulation calculations.
