Cooperative structure-directing effect of choline cation and *BEA zeolite in the synthesis of aluminogermanosilicate IWR zeolite

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.

Flexible regulation of C3^=/C2^= ratio in methanol-to-hydrocarbons by delicate control of acidity of ZSM-5 catalyst

Avery wide range of the C3^=/C2^= ratio from 0.72 to 7.56 with high C2^= ＋ C3^= selectivity of around 66%in the methanol-to-hydrocarbons process can be realized over ZSM-5 catalyst in a fixed-bed reactor.We firstly conduct a single factor experiment of acidity,demonstrating that the acidity control of MTH catalyst is crucial to adjusting light olefins selectivity.Weak Bronsted acid sites favor to high C3^= selectivity（59.0%）due to the suppression of the conversion reactions from the alkene-based to arene-based cycle,while Lewis acid sites conduce to high C2^= selectivity（39.6%） due to the promotion of the conversion reactions for the aromatics formation and steric constraints of Lewis acid sites making the aromatics crack more efficiently to C2^=.

The synthesis of pillared nickel-substituted saponite and its hydroisomerization activity

Nickel-substituted saponite clays (NiS) were synthesized. The pillared clays noted PNiS were prepared from the NiS intercalated with large inorganic cations such as [Al_(13)O_4(OH)_(24). (H_2O)_(12)]^(7+). It is found that the pillar density is correlative with aluminium content in the tetra- hedral sheet of NiS. The results from TPR indicate that the palladium loaded on samples promotes the reduction of the nickel ion in the octahedral sheet. The pillared clays impregnated with Pd^(2+) noted PdPNiS show excellent hydroisomerization property which is much better than that of nickel substituted mica-montmorillonite pillared with silicon oxide oligomer noted PdPSMM. The hexane conversion increases with the content of aluminium ion in the tetrahedral sheet, whereas the change of the selectivity of isomerization is not obvious.