Two-step Postsynthesis Method Research Articles

Highly stable VSi-beta zeolite synthesized by a post-synthesis strategy for efficiently catalyzing styrene epoxidation

To enhance the doping of vanadium in zeolites and achieve high stability, the selection of vanadium precursors containing specific vanadium species can effectively overcome this crucial problem. Two series of VxSi-Beta(A) and VxSi-Beta(N) zeolites have been prepared by a two-step post-synthesis method at pH = 1 and pH = 7. The properties and environments of vanadium in samples are investigated by UV–vis, XPS, EPR, H2-TPR and 51V MAS NMR. The bonding between vanadium and framework in VSi-Beta(A) is stronger than that of VSi-Beta(N). After the two are calcined or hydrated, the vanadium species in the former are relatively stable, while the pseudo-tetrahedral V(V) species and pseudo-octahedral V(V) species in the latter are interconverted. The changes of vanadium species in the supernatant during the preparation have been investigated by 51V static NMR. At low concentration and pH = 1, there is a unique mononuclear cation (VO2+) in the aqueous NH4VO3 solution, which is favorable for the interaction with the negatively charged hydroxyl nests generated after the nitric acid dealumination, and enables the V atoms to be tightly inserted into the framework. In styrene epoxidation, the type of V(V) species in the catalyst could significantly affect its catalytic performance, and the catalytic activity and stability of VxSi-Beta(A) are superior than that of VxSi-Beta(N).

The Synthesis of Different Series of Cobalt BEA Zeolite Catalysts by Post-Synthesis Methods and Their Characterization

Three series of zeolite catalysts Co all-silica and Co Al-containing zeolites beta were prepared for use in the selective oxidative dehydrogenation of propane to propylene. Two series of zeolite catalysts Co all-silica were prepared by a two-step postsynthesis method at pH = 2.5 and pH = 3.0–9.0, respectively, which allows the incorporation of cobalt into SiBEA zeolite in the form of isolated framework pseudo-tetrahedral Co(II) species. The incorporation of Co ions into vacant T-atom sites and their reaction with silanol groups were demonstrated by NMR and FTIR methods. The generation of Lewis acid sites without the formation of Brønsted sites was proved by FTIR using pyridine and CO as probe molecules. The state of cobalt in three series of prepared and calcined zeolite catalysts was characterized by DR UV-vis. This technique allowed to show that for low Co content (<2 wt.%) cobalt is present in the form of framework pseudo-tetrahedral Co(II) species. For higher Co content (>2 wt.%), both framework pseudo-tetrahedral and extra-framework octahedral Co(II) species are present. The Co Al-containing zeolite beta series prepared on non-dealuminated support shows the presence of extra-framework octahedral Co(II) only.

Ga(Nb,Ta)SiBEA zeolites prepared by two-step postsynthesis method: acid–base characteristics and catalytic performance in the dehydrogenation of propane to propylene with CO2

Ga(Nb,Ta)SiBEA zeolites prepared by two-step postsynthesis method: acid–base characteristics and catalytic performance in the dehydrogenation of propane to propylene with CO2

Ketonization of Propionic Acid on Lewis Acidic Zr-Beta Zeolite with Improved Stability and Selectivity

Ketonization reactions provide a feasible approach to remove oxygen and increase carbon chain length for conversion of biomass derived carboxylic acids. However, the reaction suffers from fast catalyst deactivation and low ketone selectivity. In this work, Lewis acidic heteroatom Ti-, Zr-, Ce-, and Sn-Beta zeolites were prepared using a two-step post-synthesis method and applied in vapor phase ketonization of propionic acid at 350 °C. Among these zeolites, Zr-Beta shows both the highest activity and selectivity. Characterizations indicate that Zr prefers the vacant tetrahedral site when the Zr content is 96% at a space time of 2 h. The amount of coke deposition on Zr-Beta is about 1/3 of that on H-Beta, and the structure of Zr-Beta is preserved after 60 h of reaction. The results of this work indicate that Zr-Beta zeolite is a promising catalyst for ketonization with good stability and high selectivity toward ketone.

Efficient transformation of cyclohexanone to ε-caprolactone in the oxygen-aldehyde system over single-site titanium BEA zeolite

Ti x SiBEA zeolites prepared by a two-step post-synthesis method are applied in the liquid-phase Baeyer-Villiger oxidation of cyclohexanone to ε-caprolactone in the oxygen-aldehyde system. Such method of ε-caprolactone synthesis offers the application of milder reaction conditions with the catalytic system which transforms cyclic ketones into lactones in the presence of molecular oxygen and aldehyde. They are the source of in situ peracid formation. The Ti incorporation into SiBEA involves the formation of Ti(IV) (OSi) 4 as main species and small numbers of Ti(III) (OSi) 3 –O(H)–Si sites having Brønsted and Lewis acid properties. The acidity is a key factor for efficient transformation of cyclohexanone to ε-caprolactone in the BV oxidation depending on the titanium oxidation state and environment. Among all of the studied catalysts, the highest catalytic activity is observed for Ti 2.0 SiBEA zeolite. The active catalyst of the studied BV oxidation reaction is bi-functional, possessing both the acidic and redox properties, catalyzing different reaction stages. • The incorporation of Ti into the SiBEA framework evidenced by FTIR and NMR. • DR UV–vis and XPS showed the presence of framework tetrahedral Ti(IV). • Ti(IV) (OSi) 4 sites appeared as main redox centres. • Ti(III) (OSi) 3 –O(H)–Si sites possessed both Brønsted and Lewis acid properties. • The Ti x SiBEA catalysts applied in BV oxidation reaction have bifunctional character.

The catalytic activity of microporous and mesoporous NiCoBeta zeolite catalysts in Fischer–Tropsch synthesis

Two kinds of microporous and mesoporous NiCoBeta zeolite catalysts were prepared. The effect of bimetallic zeolite preparation method, dealumination degree, the presence of micropores in the support structure and the effect of nickel addition on the activity and selectivity of cobalt-based microporous and mesoporous dealuminated and non-dealuminated zeolite catalysts in Fischer–Tropsch synthesis were determined. These catalysts were obtained by sequential impregnation (Ni3.0Co20AlBeta and Ni3.0Co20SiBeta) and co-impregnation (co-Ni3.0Co20AlBeta and co-Ni3.0Co20SiBeta). The study showed that the presence of Ni leads to a lower cobalt oxide reduction temperature and an increase in CO conversion. Nickel–cobalt zeolite systems showed high activity and selectivity throughout the lifetime of the reaction. The use of a two-step post-synthesis method and the promotion of cobalt systems with nickel allow to obtain active, selective, and stable zeolite catalysts for Fischer–Tropsch synthesis.

Zn modification of Beta zeolite: Effect on acid sites and propylene oxide rearrangement

Abstract The Lewis acid sites (LA) in catalyst plays an important role in the propylene oxide rearrangement reaction. In order to introduce more LA in Beta, Zn-Beta was prepared by two-step postsynthesis method. The results of PyIR showed that the acidity of the sample changed greatly, the Bronsted acid sites (BA) disappeared, and new LA was created with the introduction of Zn. The location of the acid sites of Zn-Beta was determined by trimethylpyridine adsorbed IR, the results showed that the new LA was distributed on the inner surface of the pore. The mechanism of propylene oxide rearrangement with Zn-Beta as catalyst was studied by in-situ DRIFTS. It was proved that the epoxy bond of propylene oxide interacted with new LA to form a transition state between the bond of C O and C O, and then converts to carbonyl of propionaldehyde. The catalytic performance of Zn-Beta was better than Beta.

Highly efficient conversion of Kraft lignin into liquid fuels with a Co-Zn-beta zeolite catalyst

Kraft lignin depolymerization to liquid fuels with high yields is crucial to the comprehensive achievement of sustainable and economic feasibility. Herein, we prepared a bimetallic Co-Zn/Off-Al H-beta catalyst through a two-step post synthesis method composed of dealumination and metal incorporation. The bifunctional Co-Zn/Off-Al H-beta catalyst efficiently converted Kraft lignin to liquid fuels, which was attributable to the synergistic effect of Co hydrogen binding sites and Zn Lewis acid sites on H-beta support. Catalytic hydrogenation with Co:Zn = 1:3/Off-Al H-beta catalyst at 320 °C for 24 h gave the highest yield of petroleum ether soluble product (81%, mainly monomers and dimers). Under these conditions, the liquefied lignin gave a higher heating value of 33.3 MJ/kg, which is a significant increase from 26.0 MJ/kg of Kraft lignin. The catalyst stability test showed excellent recyclability. This work provides a paradigm of improving lignin depolymerization efficiency via the combined use of Lewis acid and hydrogenation catalyst.

Design of Ti-Beta zeolites with high Ti loading and tuning of their hydrophobic/hydrophilic character

Abstract For heterogeneous catalysts, like Ti-Beta zeolites, the control of the material properties is very important. Due to their high surface area, large 12-ring pore channels and highly active tetrahedral isolated Ti-sites, Ti-Beta zeolites are well-known catalysts for applications in the field of oxidizing alkanes, alkenes, as well as for CO2 reduction. The drawback of many state-of-the-art synthesis methods is the limitation of the maximum amount of active sites and the control of material properties like hydrophilicity and Ti loading of the zeolite. This paper reports on the impact of the synthesis method and the variation of synthesis parameters on the material properties of the Ti-Beta heterogeneous catalyst. By using characterization techniques such as XRD, FTIR, UV-DR, Ar-sorption, H2O-sorption, ICP-MS and Raman spectroscopy, the control on important material properties of the Ti-Beta zeolite are investigated. A reproducible two-step post-synthesis method has been optimized in order to prepare high loading Ti(IV)-containing Beta zeolites, of which the hydrophobicity/hydrophilicity is tunable. The optimized method allows to synthesize Ti-Beta zeolites with a very high Ti loading up to 7.4 wt% Ti with the majority in the form of isolated tetrahedrally coordinated Ti(IV) in the zeolite framework, which is a three times higher Ti loading than Ti-Beta materials synthesized by conventional hydrothermal synthesis. This high Ti loading together with the tuning of the hydrophobicity/hydrophilicity is expected to have a positive effect on the catalytic performance of Ti-Beta zeolites.

Cobalt Based Catalysts Supported on Two Kinds of Beta Zeolite for Application in Fischer-Tropsch Synthesis

Co-containing Beta zeolite catalysts prepared by a wet impregnation and two-step postsynthesis method were investigated. The activity of the catalysts was examined in Fischer-Tropsch synthesis (FTS), performed at 30 atm and 260 °C. The physicochemical properties of all systems were investigated by means of X-ray diffraction (XRD), in situ XRD, temperature programmed desorption of ammonia (NH3-TPD), X-ray Photoelectron Spectroscopy (XPS), temperature programmed reduction of hydrogen (TPR-H2), and transmission electron microscopy (TEM). Among the studied catalysts, the best results were obtained for the samples prepared by a two-step postsynthesis method, which achieved CO conversion of about 74%, and selectivity to liquid products of about 86%. The distribution of liquid products for Red-Me-Co20Beta was more diversified than for Red-Mi-Co20Beta. It was observed that significant influence of the zeolite dealumination of mesoporous zeolite on the catalytic performance in FTS. In contrast, for microporous catalysts, the dealumination did not play such a significant role and the relatively high activity is observed for both not dealuminated and dealuminated catalysts. The main liquid products of FTS on both mesoporous and microporous catalysts were C10-C14 isoalkanes and n-alkanes. The iso-/n-alkanes ratio for dealuminated zeolite catalysts was three times higher than that for not dealuminated ones, and was related to the presence of different kind of acidic sites in both zeolite catalysts.

Fischer-Tropsch reaction on Co-containing microporous and mesoporous Beta zeolite catalysts: the effect of porous size and acidity

• The most active catalyst was Red-Me-CoSiBeta with CO conversion of 91%. • Red-Mi-CoSiBeta was less active than Red-Me-CoSiBeta. • With CO conversion of 71.6% and selectivity towards liquid products of 86.6%. • Red-Mi-CoSiBeta more selective towards isoalkanes than Red-Me-CoSiBeta. • Formation of the bigger cobalt nanoparticles is the key factor of FTS. This work deals with the investigation of the influence of the preparation procedure on the activity of microporous and mesoporous CoBeta zeolite in Fischer – Tropsch synthesis (FTS). The series of CoSiBeta, CoAlSiBeta and CoAlBeta zeolites were prepared by: i) two-step postsynthesis procedure (CoSiBeta with totally dealuminated Beta and CoAlSiBeta with partially dealuminated Beta) and ii) classical wet impregnation (CoAlBeta with undealuminated Beta), respectively. The calcination of as prepared CoSiBeta, CoAlSiBeta and CoAlBeta zeolites at 500 °C, for 3 h in the air and then reduction by treatment in flowing H 2 at 400 °C for 1 h allows to obtain Red-C-CoAlBeta, Red-C-CoAlSiBeta and Red-C-CoSiBeta catalysts with different properties in Fischer – Tropsch reaction. The two-step postsynthesis method allowed obtaining very active, more stable and more resist to carbon deposition catalysts. Two series of zeolite catalysts were prepared using microporous (Mi) and mesoporous (Me) supports. The most active catalysts in Fischer-Tropsch synthesis was Red-Me-CoSiBeta with high CO conversion of 91% and selectivity towards liquid products of 88.9% and Red-Mi-CoSiBeta with CO conversion of 71.6% and selectivity towards liquid products of 86.6%. Such results seem to be related to the formation of the larger cobalt nanoparticles on SiBeta support than on HAlSiBeta and HAlBeta supports. Larger particles exhibit weaker interaction with the support and hence, higher activity in Fischer-Tropsch synthesis. Red-Mi-CoSiBeta zeolite catalyst shows much higher selectivity towards isoalkanes than Red-Me-CoSiBeta with the ratio isoalkanes/n-alkanes of 1.32 for Red-Me-CoSiBeta and of 2.38 for Red-Mi-CoSiBeta.

Dealuminated Beta Zeolite Modified by Alkaline Earth Metals

Alkaline Earth metals (Mg, Sr, and Ca) were incorporated into the dealuminated mesoporous beta zeolite (DeAlBeta) by the two-step postsynthesis method. Physicochemical properties of both unmodified and alkaline Earth metal-modified DeAlBeta zeolite were characterized by XRD, DR UV-vis, FTIR, TPD of NH3 and CO2, NMR, and XPS. The dealumination of beta zeolite led to decrease of its acidity and basicity. The incorporation of alkaline Earth metals into the framework of dealuminated beta zeolite did not affect its structure. The modification of DeAlBeta with a small amount of alkaline Earth metals increases the number of acidic centers, which may be related to the formation of framework Mg (Ca or Sr) (II) Lewis acidic sites.

Experimental Evidence of the Mechanism of Selective Catalytic Reduction of NO with NH3 over Fe-Containing BEA Zeolites.

Various temperature-programmed techniques were used as tools in mechanistic studies of selective catalytic reduction (SCR) of NO with ammonia in the presence of Fe-containing BEA zeolites. Moreover, FTIR studies of adsorbed NH3 and NO were conducted to determine the interactions of reactants with the catalyst surface. Iron was introduced into BEA zeolite by three different methods: i) two-step post-synthesis; ii) conventional wet impregnation; iii) ion exchange. The catalytic activity was dependent on the method used for iron introduction. The reactivities of NH3 and NO adsorbed on iron-modified zeolites obtained by impregnation and ion-exchange methods were higher than those measured for the catalyst obtained by a two-step post-synthesis method. The activity of Fe-containing zeolites in SCR was related to the form of deposited iron species, as well as to the nature, strength, and concentration of acid sites. Possible reaction pathways of NO reduction over the FeBEA zeolite catalysts were presented and discussed.

Sn-BEA zeolites prepared by two-step postsynthesis method: Physicochemical properties and catalytic activity in processes based on MPV reduction

Sn0.5SiBEA and Sn2.0SiBEA zeolites obtained by two-step postsynthesis method were characterized by several physicochemical techniques (namely, NMR, Mössbauer, XPS, DR UV-vis and IR spectroscopies) and used in the study of Meerwein–Ponndorf–Verley (MPV) reduction as well as with the subsequent reaction of etherification, that is, conversion of (i) cyclohexanone with 2-propanol, (ii) 4-methoxybenzaldehyde with 2-butanol, and (iii) HMF with butyl alcohols (1-butanol, 2-butanol or isobutanol). The results have shown that in the case of cyclohexanone, MPV reduction to cyclohexanol occurs on both Sn0.5SiBEA and Sn2.0SiBEA zeolite catalysts with a higher degree of conversion in the presence of Sn2.0SiBEA. For 4-methoxybenzaldehyde a tandem process was observed consisting of MPV reduction with 2-butanol to 4-methoxybenzylalcohol followed by its etherification with 2-butanol to 4-methoxybenzyl sec-butyl ether. Higher conversion of aldehyde was achieved on the catalyst with higher amount of tin. The zeolites were active in HMF conversion with butyl alcohols. However, a tandem process including MPV reduction with the next formation of furanic diether was achieved only in the presence of secondary alcohol at test conditions.

Cobalt-containing BEA zeolite for catalytic combustion of toluene

Co-containing HAlBEA zeolite was obtained by conventional wet impregnation of HAlBEA zeolite with an aqueous Co(NO3)2.6H2O solution, whereas Co-containing SiBEA zeolites were prepared by a two-step post-synthesis method. This approach consists of, in the first step, dealumination of parent BEA zeolite to obtain an aluminium-free SiBEA support and then, in the subsequent step, contact of the obtained material with an aqueous solution of cobalt nitrate. As shown by X-ray diffraction and low-temperature N2 adsorption, the dealumination of BEA zeolite and introduction of cobalt ions did not involve destruction of zeolite structure, and only insignificant blocking of pore system was observed after introduction of high amounts of cobalt. Nevertheless, clear changes in acidity were found by FTIR of pre-adsorbed pyridine after dealumination of parent BEA zeolite and introduction of cobalt ions. The presence of Lewis acid sites resulted in enhanced selectivity to CO and benzene formed as by-products in the toluene combustion. Therefore, SiBEA zeolite was chosen as a support for an introduction of various amounts of Co into the zeolite structure (the intended Co contents of 3.0–9.0wt%). Depended on the amount of the introduced Co, cobalt was incorporated into the framework of BEA zeolite as isolated mononuclear Co(II) species, small Co(II) oxide clusters and/or Co3O4 crystallites distributed in the whole zeolite structure. The chemical environment and dispersion of cobalt species were studied by transmission electron microscopy (TEM), FTIR of pre-adsorbed NO, UV–vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy (XPS). Temperature-programmed reduction of hydrogen (H2-TPR) was also performed to determine reducibility of the Co-containing SiBEA zeolites. It was confirmed that siliceous SiBEA zeolite was the excellent support of Co3O4, which was in turn recognized as the main active phase in the total oxidation of toluene. The best catalytic performance was achieved over the catalysts containing at least 0.05mmol of Co in the form of Co3O4 per 1g of SiBEA zeolite.

Influence of the nature and environment of manganese in Mn-BEA zeolites on NO conversion in selective catalytic reduction with ammonia.

Manganese-containing BEA zeolites, MnxSiBEA (x = 1-4 wt%) and Mn(I.E.)AlBEA, were prepared by a two-step post-synthesis method and a conventional wet ion-exchange, respectively, and applied as catalysts in the selective catalytic reduction of NO with ammonia (NH3-SCR). The physicochemical analysis of zeolite properties by high-energy-resolution fluorescence-detected XANES (HERFD-XANES) and X-ray emission spectroscopy (XES) uncovered that the coordination, geometry and oxidation state of Mn species are strongly related to the preparation method. Additionally, the study of catalyst acidity by FTIR spectroscopy with CO and pyridine probe molecules provided important insight into the number and type of acidic centres present on the catalyst surface. The catalytic results revealed that NO conversion depended on the state and content of Mn. The zeolites obtained by the two-step post-synthesis method and with a low Mn content were very active in the medium temperature range (NO conversion ∼100%) with simultaneous high selectivity to N2 due to the presence of isolated, framework Mn(iii) and Mn(ii) species. The N2O formation was especially high in the case of catalysts containing extra-framework polynuclear Mn species and negligible in the case of Mn(I.E.)AlBEA containing predominantly isolated, extra-framework Mn(ii) species.

Influence of preparation procedure on catalytic activity of PdBEA zeolites in aqueous phase hydrodechlorination of 1,1,2-trichloroethene

Pd-loaded BEA zeolites containing 1 wt % of Pd were prepared by a two-step postsynthesis method (PdSiBEA and PdSiAlBEA) and a conventional wet impregnation (PdHAlBEA). Modification of BEA zeolite resulted in the introduction of Pd ions into zeolite framework as pseudo-tetrahedral Pd(II) and extra-framework octahedral Pd(II) evidenced by XRD, DR UV–vis and TPR measurements. Calcination of as prepared zeolites in air at 773 K for 3 h and then reduction in 10% H2/Ar flow at 873 K for 3 h led to obtain red-C-PdSiBEA, red-C-PdSiAlBEA and red-C-PdHAlBEA zeolites with different Pd nanoparticles size distributions showed by TEM. These zeolite materials were found to be active catalysts in aqueous-phase hydrodechlorination of 1,1,2-trichloroethene (TCE). The conducted catalytic reactions have demonstrated that the rate and course of TCE hydrodechlorination depend on the catalysts preparation method and Pd nanoparticles size.

Direct synthesis of nitrogen-doped mesoporous carbons for acetylene hydrochlorination

Nitrogen-doped ordered mesoporous carbon (N-OMC) catalysts were directly synthesized using SBA-15 as a hard template and sucrose as a carbon source. Urea, which was used as the nitrogen source, was carbonized with sucrose. A 3.6 wt% nitrogen doping of the carbon framework was achieved, with more than 70% of the nitrogen incorporated as quaternary nitrogen species. Only 0.2 wt% nitrogen doping, with only 32.7% quaternary nitrogen incorporation was obtained in an N-OMC catalyst (N-OMC-T) prepared using a two-step post-synthesis method. The acetylene hydrochlorination activities of N-OMC catalysts prepared via the one-step method were higher than that of the N-OMC-T catalyst because of the higher nitrogen loadings.

Effect of the niobium state on the properties of NbSiBEA as bifunctional catalysts for gas- and liquid-phase tandem processes

NbSiBEA zeolites contained isolated framework mononuclear Nb(V) (Nb0.7SiBEA) and a mixture of framework mononuclear and extra-framework polynuclear Nb(V) (Nb2.0SiBEA) were prepared by two-step postsynthesis method as evidenced by XRD, NMR, DR UV–vis and FTIR. DR UV–vis showed that two types of framework mononuclear Nb(V) are present in Nb0.7SiBEA, while Nb2.0SiBEA mainly contained isolated mononuclear Nb(V) in the framework of zeolite and polynuclear Nb(V) in the extra-framework position. FTIR with pyridine and 2,6-di-tert-butylpyridine as probe molecules showed that major amount Lewis and weak Brønsted acidic sites are formed by incorporation of niobium in the framework of zeolites as mononuclear Nb(V). The catalytic properties of Nb-containing zeolites were investigated in tandem processes of ethanol conversion into 1,3-butadiene (gas-phase) and synthesis of unsymmetrical ethers from aromatic aldehyde and aliphatic alcohol (liquid-phase). It has been found that Nb0.7SiBEA catalyst, containing only isolated framework mononuclear Nb(V) is more active than Nb2.0SiBEA in the conversion of ethanol and ethanol/acetaldehyde mixture into 1,3-butadiene, MPV reduction of crotonaldehyde with ethanol and etherification of 4-methoxybenzyl alcohol with 2-butanol. The higher specific activity (turnover number/frequency) of Nb0.7SiBEA than Nb2.0SiBEA catalyst has been revealed for gas- and liquid-phase tandem processes.

Influence of the postsynthesis preparation procedure on catalytic behaviour of Ag-loaded BEA zeolites in the hydrodechlorination of 1,2-dichloroethane into value added products

Two silver-containing BEA zeolites prepared by a two-step postsynthesis method (Ag2.0SiBEA) and a conventional wet impregnation (Ag2.0HAlBEA) showed a high activity in the conversion of 1,2-dichloroethane (1,2-DCE) into value added products with 100% selectivity into ethylene and 100% selectivity into vinyl chloride, respectively. The role of the silver in two kinds of studied catalysts was different. The HRTEM, STEM with EDS elemental mapping showed that the excellent activity of silver containing catalyst, prepared by two-step postsynthesis method, in hydrodechlorination of 1,2-DCE was strongly related to the presence of very small (<3nm) metallic nanoparticles, resistant for the deactivation by chlorine poisoning. On the other hand, introduction of Ag ions into the HAlBEA zeolite led to a decrease of the coke formation during hydrodechlorination process on red-C-Ag2.0HAlBEA zeolite catalyst. As a result, it was observed lower drop of activity of red-C-Ag2.0HAlBEA catalyst than HAlBEA over HDC reaction with maintaining 100% selectivity to vinyl chloride.